Amp gurus...Please help with my Hot Rod Deluxe

[jazzrat]

Here's the deal....5 year old HRD. Works great but is starting to sound flabbly. This is just the clean channel as I never use the drive channel.
I retubed thinking it was time but that did not help with the bottom end breaking up. Could it be the stock Eminence speaker has gotten soft?
Any ideas?

[kewlpack]

Well - you know how it is...

Everyone gets flabby in their old age! 8-[
:rofl: :rofl: :rofl: :rofl: :rofl: :rofl: :rofl: :rofl: :rofl: :rofl:

[jazzrat]

Hey... I resemble that remark! :mrgreen:
Maybe it's just my ears have gone flabby along with my midsection

[Crunchyriff]

My wife tried to retube me once... couldn't get me to hold still. 8-[

[stephen]

My wife tried to retube me once... couldn't get me to hold still. 8-[

:-s

:crazy

:ROFL

[kewlpack]

Jazz - maybe go play a new HRD at a store and see if it is actually going "bad". Just to compare.

If you have another cab, maybe you can hook up the HRD head to that.

That would clue you in on if it is just the speaker.

Just an idea tho. :)

[refin]

All kidding aside,it probably is a tube....bad or weak power tubes make the low end flabby,because the low notes demand more juice to push.
Also,preamp tubes---the last small preamp tube before the power tubes is usually the driver stage,which takes the shaped tone from the preamp and amplifies it.

[Crunchyriff]

yeah- I'd suspect tubes too, but then again, depending what kind of demands have been put on the speaker, and knowing std-issue amps usually get "lowest bidder" pieces, it may well be the speaker.

I think Jazzrat already threw a new set o tubes in. (he didn't specify all the tubes or just preamp or power amp- I'm assuming power tubes)

Hmmm...if it's not the speaker, & not the tubes, Maybe a cap going bad?

[Pearly Gator]

What tubes got replaced? Preamp, power or both? What brand did you put in? Did you get the amp rebiased?

Gator

[jazzrat]

The amp was sounding funny with the stock Groove Tubes and
EH 12AX7's. The power tubes and the phase inverter (#3) were factory while the other two preamp tubes are EH 12AX7's.
I replaced the power tubes with a matched pair of Svetlana 6L6GC's.
I got them from Lord Valve. He sell them as drop in replacements for Groove Tubes, so I did not rebias. I will do that at some point.
I also replaced the #3 tube with another EH 12AX7.

Long story short....it sounds identical. If not the speaker should i suspect the other two preamp tubes. They are a couple years old.
Thanks guys for all your comments

[dmw]

I doubt that the speaker has anything to do with it. I've got speakers from the 1960's that still perform well. The edge suspension will get more pliable over time, but there's also the spider assembly that controls the cone. It takes alot of abuse to wear-out a guitar speaker (or any speaker, for that matter).

[Brian]

My Boogie MKII B is doing the flabby thing with humbuckers along with what I think is microphonics since it gets feedback on a sustaining note way easier than my Sedona. I never drive the power tubes hard and keep 2 of them at idle with the 50 watt setting. Mike at KCA thinks it's preamp tubes. It has been a very long time since it's had new tubes.

I'm not a tube amp expert (although I should be... I maintained tube-based avionics systems for 7 years), so it's in the shop for a complete checkout and restore.

However apparently unlike your HRD, early Boogie Mark series are known for flab with humbuckers at high gain settings; I played a Telecaster and Stratocaster back then and didn't have the problem. I stumbled onto some info on the Smooth & Slim (http://home.earthlink.net/~ayan/sands.htm) that i might try if the problem still exists with my Zion.

[Crunchyriff]

....these little Boogies had something no other amp had: a bunch of extra gain stages that would make your guitar sustain for days. The amp was also very heavy on midrange, and its basic tone therefore contrasted quite a bit with, say, the scooped midrange sound made famous by Marshall amps... (from the link)

Now these guys may know what they are doing for the "mod"; but they are way off about the "scooped midrange made famous by Marshall amps"
We're talking about 1972 here. There were no scooped Marshalls back then. EVER.

First off, Marshall is THE pioneer of midrangey, clangy rock crunch. PERIOD! \:D/ The 60's and 70's were two decades full of "Marshall midrange", Chock full o' clang. The Boog simply added the ability to have a quite saturated gain stage, (and a very loud amp in a small pkg.) but at the cost of how the preamp was voiced, hence the "mud" issue. Of course, the difference in 6L6's in the Fender circuit vs. Marshalls 6550's and EL34's factor in here, too. Quite frankly, with humbuckers, the mid voicing of the boog was great for solos, but horrid for crunchy rhythm work, due to the specific mid frequencies emphasied in the boogs.

Marshalls were NEVER known for their 'scooped midrange' until the mid 80's, when groups like RATT, etc brought into the equation added pieces like the Furman PQ3, boosting certain mid bands, but scooping others. Metal & Thrash just took the concept even further. In fact, the older Marshall Plexi, JTM, and JMP aluminum panel preamp circuits were all about midrange. You couldn't scoop the mids on the amp itself- not without some sort of outboard processing gear, and mids is where a guitar rightfully sits in the mix. That's what made the avg 60's and 70's Marshalls so easy to work with and sound 'right'- the right preamp voicing.

Just a little clarification and edification for my tone-bretheren!

[prscustom24]

Here's the deal....5 year old HRD. Works great but is starting to sound flabbly. This is just the clean channel as I never use the drive channel.
I retubed thinking it was time but that did not help with the bottom end breaking up. Could it be the stock Eminence speaker has gotten soft?
Any ideas?

Pull any tubes you have not yet replaced and reseat them -- just pull 'em out and plug 'em back in the same sockets. Come back and let us know if that made any difference.

[Crunchyriff]

Might try cleaning the pins and sockets, too. of course, you may want a tech to do the sockets if you haven't discharged the caps (if you don't know how do this yourself...or don't want to.)

The voltages can kill you!!

I know guys that swear by stuff like kramolin used very, very sparingly on the pins once everything is cleaned up.

[TOO LOUD]

Sounds like a good reason to get a new amp?? Ha Ha. My wife is too smart for that one.

[Brian]

...Now these guys may know what they are doing for the "mod"; but they are way off about the "scooped midrange made famous by Marshall amps" We're talking about 1972 here. There were no scooped Marshalls back then. EVER.Please understand I don't have any need to stick up for the guys at Ayan Enterprises. I played my '67 Telecaster and early 80s Japanese Fender Stratocaster through my MK IIB and tend to disagree with what he said about Strat users are probably very familiar with the rather shrill tone that results when using these guitars in conjunction with Boogies set for overdrive.I have yet to try the S&S, I might not like it, and I'll be kind of upset :hissyfit if I pay the $$ to get my amp retubed and tuned up then see the need to shell out another ~$140 for the S&S and it does not meet the expectations he set for me to smooth out and tighten up the distortion with my Zion through my Boogie.

It is mentioned that he purchased his Mark I in 1974 but I didn't read him mention a date when Soon, Mesa became famous and started pumping out with a bunch of other models... Nor does he say when ... other amp companies started copying the Boogie's cascaded preamp. But when they first came out, these little Boogies had something no other amp had: a bunch of extra gain stages that would make your guitar sustain for days. In fact I still have the early 80s catalog from when I bought mine and the MK II was the only model available. I'd hardly say that's a bunch of models after the Mark I. I remember looking closely at amps to replace my old Sunn back in the early 80s and maybe I'm just senile :crazy but I don't remember any others that had that Boogie cascaded preamp sound at the time :???: . And I also didn't see a date mentioned for ...the scooped midrange sound made famous by Marshall amps. I'm no Marshall historian but fwiw, makes sense to me.

[refin]

Might try cleaning the pins and sockets, too. of course, you may want a tech to do the sockets if you haven't discharged the caps (if you don't know how do this yourself...or don't want to.)

The voltages can kill you!!

I know guys that swear by stuff like kramolin used very, very sparingly on the pins once everything is cleaned up.

Another cause,for sure!
If tubes have been changed alot or pulled,the sockets can get loose...retension with a jeweler's screwdriver,but first.BLEED THE CAPS!The late great Cesar Diaz used Gunk Carb cleaner on tube sockets,and I've done the same with great results.
Have you considered a cold solder joint somewhere in the signal path? The Blues Series amps are not point to point,but circuit board,and the heat from the tubes goes up and can even warp the board.Also,parasite dust and dirt can get inside and cause weird oscillations.Blow the amp chassis out with compressed air,and tighten up everything---speaker,baffle board,transformers,jacks,ect.Remember Murphy's law!
Don't mean to rattle on here,but as a vintage amp owner and user,I've learned that the smallest things can cause a poopy sound.

[Swarty]

Was the amp biased when you changed output tubes? Flabby bottom is a classic symptom of worn power tubes (or under biased). If you have a chance, try plugging the amp into a seperate speaker cab to see if it could be the speaker.

[dmw]

I'm old enough to have been around for the early Marshalls. I just want to say that Crunchy is right about Marshalls, and the "scoop" comes from how the amps have been EQ'd.

Marshalls that I'm familiar with produce a big, fat round tone, which means that they're not really not emphasizing a particular tonal range on their own, although the choice of cabs (sealed vs. open, and multiples) can greatly affect the ultimate tone.

Why I never owned a Marshall stack? In my early playing years I played through old blackface Fender tubers, and was satisfied with what I had. Later I never owned a vehicle large enough to haul one around. Now I don't want to schlep one around, and I can't afford a carting company or roadie. Today I'm looking for the smallest amp with the greatest output for it's size. So I play through a 50 Watt Boogie combo. There are others out there these days that are good or even better choices in combos.

[jazzrat]

Was the amp biased when you changed output tubes? Flabby bottom is a classic symptom of worn power tubes (or under biased). If you have a chance, try plugging the amp into a seperate speaker cab to see if it could be the speaker.

I did not rebias. I just thought I would try a quick change to see what would happen. The change seems to have been gradual. Unfortunately
the only tube amp tech in our area is not a musician. In fact the last time I took the amp to him I aked him to check the bias. He said the bias was fixed on the HRD when I know for a fact it is not. (The manual show a bias adjustment) I do not have much faith in him.

You would think as big a guitar junky as I am I would learn to work on the things but I just don't have the interest I guess.
I'm about ready to trade the thing off and get another solid state amp.

[kewlpack]

I'm about ready to trade the thing off and get another solid state amp.
w00t!!! Get a Line 6 Flextone III XL - super duper amp. ;) :angel

[jazzrat]

Thanks Kewlpack! I'm looking for suggestions. The Fender 1000 is another
i am considering.

[kewlpack]

Yep,

I loved my Stage 1000. Since the Flex III XL essentially does those tones (and many more), I traded my Stage 1000 for a MiM Standard Strat... and all is well! :mrgreen:

Be sure to play with all the offerings in your budget range. There's some good stuff lately!

[Crunchyriff]

Brian IIRC,

the date factor I mentioned was 1972, in which these guys mentioned that the Boog came on the scene- and contrasted it to the mid-scooped Marshalls "that Marshall was so known for". It's a matter of context. Like I said earlier, the "scooped Marshall" thing happened as a result of outboard processing, more than 20 years after that little 1st boog combo came out; and by 1972 had established nearly a decade of midrange Marshall "clang". SO I'm giving some factual clarification in context here.

FWIW, AS far as I'm concerned, 95% of the good boogies are the old ones from that era, with few exceptions. I once was a boog user. I am not now. That doesn't mean I'll never own another. Given my track record with them it's unlikely, but not impossible- not to mention Boogs WAY over the top hype and marketing journalism which I despise. (which is another issue entirely)

Relax, man I'm not hammering you, or going after you personally. We're all friends here... AND family!

The bottom line is these guys have come up with a mod to make the old boog even MORE flexible- and that's great news. I'm just distinguishing the wheat from the chaff in the article, that's all.

Oh, one more thing Brian- friends don't let friends go solid state! :mrgreen:

[prscustom24]

Was the amp biased when you changed output tubes? Flabby bottom is a classic symptom of worn power tubes (or under biased). If you have a chance, try plugging the amp into a seperate speaker cab to see if it could be the speaker.

I did not rebias. I just thought I would try a quick change to see what would happen. The change seems to have been gradual. Unfortunately
the only tube amp tech in our area is not a musician. In fact the last time I took the amp to him I aked him to check the bias. He said the bias was fixed on the HRD when I know for a fact it is not. (The manual show a bias adjustment) I do not have much faith in him.

You would think as big a guitar junky as I am I would learn to work on the things but I just don't have the interest I guess.
I'm about ready to trade the thing off and get another solid state amp.

OK, but did you try my suggestion? What happened?

[jazzrat]

Yeah Mike, sorry I did not respond. I did at some point pull all the tubes and used some contact cleaner. I then replaced them and made sure they were well seated.
It did not seem to help.

[prscustom24]

Next step, then, is to rebias the amp. Count me ROTFLMAO when you said that Lard Valve sells "drop in" replacements, he's got no idea what he's matching up to, really, unless you were able to provide him exact transconductance values directly from the individual bottles.

So, if you have a good DVM and the schematic and parts layout drawing, you should be ready to tackle this. Any questions?

[jazzrat]

Thanks Mike,
I would need to round up a meter, which I could do. I'm open to learning to do it but I've been put off by the whole "stick your hand in the wrong place and die" thing. :mrgreen:
I have been to the Hot Rod Dlx. page.
http://studentweb.eku.edu/justin_holton/
seems like some good info. Does the step by step stuff look accurate and safe?

[prscustom24]

Yes, he's done a very good walk-thru, except in step 3b, ignore this: "Get a screwdriver and turn the bias pot all the way to one side, and then the other. Now you have a feel for the pot. Adjust the pot so that it's right in the middle—this is a good starting point."

The first thing you want to know is where are your tubes running now? It's a point you can return to if necessary. Then, adjust from there.

[jazzrat]

What about the bleed the caps off deal?

[prscustom24]

Not necessary, 'cause you're gonna just fire the amp back up and recharge the things. You're not going anywhere near the high voltage caps. Keep the screwdriver tip aimed at the pot, which is in an area of the circuit operating at minus 55 volts or so, nothing lethal. The probe tip from your meter is going into a corner of the circuit board that's within a volt of ground. All in all, quite safe. And take the guy's recommendation, do one thing at a time: apply the probe for a voltage measurement, set the probe down, pick up the screwdriver, adjust the pot, set the screwdriver down, pick up the probe, etc., all with one hand. Keep the other hand in your pocket.

At my level of experience, I know to clip the probe using an IC clip lead to the cathode resistor R66 on the back side of the board and then I've got continuous measurement while adjusting R82. You might have clearance for that with the right probe clip, but if in doubt, do it by the procedure above. And relax. :-)

[Ravindave_3600]

If you try everything in the world, and can't get your tone back, bring it up here to Doyle. He'll listen to it, give you a quick diagnosis and, if you want him to work on it, do a good job at a fair price. And hey, I'll even buy you lunch. Or at least coffee.

[jazzrat]

Thanks Dave,
I'll have to remember that. I'd have to schedule with him to come up and
have it done the same day but I might get to that point. I'm trying to either get up the nerve to work on it myself or fugitaboutit and have a pro do it.

[Crunchyriff]

I'm not a huge Lord Valve fan, but in all fairness, Lord Valve offers drop-in replacements for such as Boogie's STR420 spec (for example), which is no different than the spec they (Boogie) sets themseves and the system they use for most of their customers. Other Companies such as Traynor, etc have made their specs available to LV to enable good matches without a rebias on the circuit.

This of course is done on behalf of the user who wants a level of consistency and no-hassle re-tubing without bench work while out in the field. I think it's a smart concept that more amp mfg's should consider. Some have, but many don't.

Of course, with the given nature of tubes, nothing is ever 100% bulletproof, but it goes a long way towards ease of service.

[jazzrat]

Lord Valve claims that he can test to assure that the matched pair you get is in a range that is very close to the published specs of the factory tubes. In my case the White series Groove Tubes, but as I have already exibited, I don't know sicum about tube amps so I'll believe anybody :dunno

[prscustom24]

I'm not a huge Lord Valve fan, but in all fairness, Lord Valve offers drop-in replacements for such as Boogie's STR420 spec (for example), which is no different than the spec they (Boogie) sets themseves and the system they use for most of their customers. Other Companies such as Traynor, etc have made their specs available to LV to enable good matches without a rebias on the circuit.

This of course is done on behalf of the user who wants a level of consistency and no-hassle re-tubing without bench work while out in the field. I think it's a smart concept that more amp mfg's should consider. Some have, but many don't.

Of course, with the given nature of tubes, nothing is ever 100% bulletproof, but it goes a long way towards ease of service.

Crunchy, it's a fine idea born of a certain naivete' regarding manufacturing variation. It'll never be enough to have just the specs. And the idea that any one brand's output is consistent from one point in time to the next is itself wishful thinking at best. I'd want to know if LV can interpret x-bar and R charts and whether the manufacturers are supplying those to him as well. Doubtful. Then consider the component drift in the amp itself, and the whole thing is a moving target.

[prscustom24]

Lord Valve claims that he can test to assure that the matched pair you get is in a range that is very close to the published specs of the factory tubes. In my case the White series Groove Tubes, but as I have already exibited, I don't know sicum about tube amps so I'll believe anybody :dunno

These are shot-in-the-dark attempts to narrow and group the range of variation in the tube parameters, but you have to realize that there's still variation within those ranges, and it's enough in most cases that players still object to the audible differences. Bottom line: rebiasing is the only sure way to get the tubes doing what you want them to do.

[Crunchyriff]

Bottom line: rebiasing is the only sure way to get the tubes doing what you want them to do.

I would agree with this 100%. What I believe the pre-spec'd logic MAY be, is to get some components that operate in "ballpark range", and if he's testing them with a hickcok, or other quality mutual-conductance tester, this may in fact be possible. It would be enough for a player to be able to slap in a set of tubes at the last minute if something goes bad, and get you through a gig without too much worry. IF this is the premise, then I'm all for it.

Of course, with drift and tolerances as they are and what not, it's always best to get the amp on a bench, and do it "right". That, and many players like their bias set differntly than "factory spec" anyway. Some like hotter bias, some particular circuits (like the Marshall DSL) actually sound better biased a bit colder than stock. Usually (as you know) a 'cold' bias is the way they leave the factory for warranty issues to be a bit diminished.

Some players don't get this technical, and if the amp works, they are happy. Others have more pickier/tuned ears.

[Brian]

Brian IIRC, the date factor I mentioned was 1972...I talk (type) too much. I was just trying to say that I read Carlos' (from Ayan) statement differently.
Relax, man I'm not hammering you, or going after you personally. We're all friends here... AND family!I sure didn't mean to imply that I felt hammered. I have no personal stake in anything you mentioned. We are all Brothers and Sisters in Christ here. That's better than a lot of "families". Oh, one more thing Brian- friends don't let friends go solid state! :mrgreen:I didn't say anything about solid state. :dunno But now you've crossed the line!
(I'm kidding! ;) )

Acoustic Image, Evans (I have an AE-200), and Polytone mfg the best jazz amps on the planet... all solid state. \:D/

[prscustom24]

Crunchy,
Here's my argument against: say you're a player with tubes out of the low end of the 'Red' group (you don't actually know this, you just know they're 'Red' group tubes) and you like to bias them hot. LV sells you a matched pair of 'Red' tubes, but they happen to be from the high end of the 'Red' range (he doesn't know exactly what you have, either, nor how the amp was rebiased after it left the factory, just that his tubes "meet" the 'Red' spec). You drop them in there, and the next thing you see is the plates glowing cherry red, because that bias level is all wrong for tubes with that much higher mu. Maybe you get the amp shut down before the tubes self-destruct and take grid resistors and maybe the tube sockets with them, maybe not. Either way, you don't finish the gig with that amp.

I think marketing the color codes as a way of preselecting for a particular bias range, i.e., a more aggressive or less aggressive sound palette, is fine, but to suggest it as a way to avoid rebiasing, that's asking for trouble.

<Soapbox mode> = Off

[Crunchyriff]

PRS24-

Are you talking about red group as per GT? I hear what you are saying, and I agree with your premise here. But when LV has a set of tubes that meets the Mesa (for example) STR420 rating, I could go with that. I mean, boogie does.

I'm not certain of all of LV's rating sys, but when he says he can send me a STR420 rated set of tubes for my MESA amp (which, btw, I don't owe own anymore) I'd be comfortable with that. aside from that, and that alone, I'd probably be inclined to slap that bad boy on my tech's bench and have the bias set correctly...perhaps even to my ear. (I've done this before)

I have a Traynor combo that I have treated so un-like anythign else I own. it has a "self biasing" circuit, adn I bought a better than stock set of glass very closely matched, slapped the tubes in, and have been playing it that way for almost two years. No problem.
Is it optimum? NO. but it works. My old Marshalls, OTOH, I always do correctly. My last Soldano was a "fixed bias", but I always took it in anyway. As hands-on a guy as I usually am, I should do my own servicing, but quite frankly, an unexpected date with 450+ volts just doesn't excite me at all...

Brian- I'm not thinking you're ragged at me, I was just checking to see that you weren't taking anything I said at gut-level. Internet chat can be weird at times in this regard.

[prscustom24]

Crunchyriff: Are you talking about red group as per GT? I hear what you are saying, and I agree with your premise here. But when LV has a set of tubes that meets the Mesa (for example) STR420 rating, I could go with that. I mean, boogie does.


Yes, I'm talking about variance in gain, whereas you're talking about the STR420 as a tube type. I don't doubt there are a number of suppliers approximating the plate characteristic curves of the STR420. But making it follow the correct load line, that's the important point, and that's where the bias pot comes in.

Fender, for a while in the '90s, brought the bias pots and test jacks out to the chassis back panel on their 100-watt amps ("Tonemaster", "The Twin", etc). I don't know if they still do. It was one of the best things Fender ever did for musicians from a maintenance standpoint, although amp techs will disagree, since it meant fewer bread & butter jobs for them. It made the bias job truly safe and easy to do in the field. It's a shame it hasn't caught on.

[Crunchyriff]

Yes, I'm talking about variance in gain, whereas you're talking about the STR420 as a tube type.

Uhh...no, what I am referring to is the numerical rating sys that Mesa/Boog gives their various 6L6 and EL34's. I understand the gain rating sys that GT has used for quite awhile now. But Boog has say, an amp that is spec'd for , say, an STR420 EL34 (or whatever) tube. Aren't you a boog player? Thought you might be familiar with that. Whatever that specific amp is spec'd for, Boog has developed a sys that (according to boogie) allows you a no hassle, drop-in replacement for that given amp.

Aiken and a few other Boutique amp builders have incorporated test jacks and bias pots on the chassis rear, too. That is a great feature. I wish they all would do that.

I'll quite hijacking the thread now... :oops: :angel

[jazzrat]

OK, further adventures....
I took the amp in the local music store that I bought it from. These guys have good ears and years of experience with Fender amps.
He heard what I was hearing so at least I know it's not me. He did not think it was anything electrical. His suggestion was possibly an old speaker or a sympathetic chassis vibration.

When I got it home I tried all kinds of tube swaps just looking for something. I also swapped out the speaker for fun.
Conclusion: He suggested it and may be right...I am just pushing the amp in ways I never have before. I did notice one thing. I tend to run the mid-range pretty high and treble and bass down to tame my Tele.
If I back the mids down to 5 with the treb. & bass it cleans up quite a bit.
I may also be the speaker change.

I think its possible, even likely that the bias has drifted after 5 years so I need to check that. I am feeling more confident after pulling the chassis for the speaker swap. I looked around in there and got the lay of the land. I need to get a meter and check the bias.

Thanks everyone for their suggestions...I even enjoyed the hijacks Crunchy! ;) :mrgreen:

[Crunchyriff]

Speaker changes are a great way to shape/improve your tone. Go for it!! A single speaker in a open-backed cab can only take so much if you're really mashin on it...

[prscustom24]

Yes, I'm talking about variance in gain, whereas you're talking about the STR420 as a tube type.

Uhh...no, what I am referring to is the numerical rating sys that Mesa/Boog gives their various 6L6 and EL34's. I understand the gain rating sys that GT has used for quite awhile now. But Boog has say, an amp that is spec'd for , say, an STR420 EL34 (or whatever) tube. Aren't you a boog player? Thought you might be familiar with that. Whatever that specific amp is spec'd for, Boog has developed a sys that (according to boogie) allows you a no hassle, drop-in replacement for that given amp.

Aiken and a few other Boutique amp builders have incorporated test jacks and bias pots on the chassis rear, too. That is a great feature. I wish they all would do that.

I'll quite hijacking the thread now... :oops: :angel

Marketing something as "STRxxx" sure sounds suspiciously like an attempt to associate with the historic Sylvania types, don't it? And, considering the polar-opposite Mesa design philosophy of fixed-bias only, which makes it absolutely essential that their tubes fall within an ultra-narrow range: by the time the tubes are screened for that many parameters, they probably deserve their own unique type numbers. That's arguably working for Mesa alone among all the amp manufacturers.

Not sure how I gave the impression I was a Boogie player; I never warmed up to their "unique" tone. I may have mentioned having the odd one on the bench in the days when I serviced amps.

[prscustom24]

OK, further adventures....
I took the amp in the local music store that I bought it from. These guys have good ears and years of experience with Fender amps.
He heard what I was hearing so at least I know it's not me. He did not think it was anything electrical. His suggestion was possibly an old speaker or a sympathetic chassis vibration.

When I got it home I tried all kinds of tube swaps just looking for something. I also swapped out the speaker for fun.
Conclusion: He suggested it and may be right...I am just pushing the amp in ways I never have before. I did notice one thing. I tend to run the mid-range pretty high and treble and bass down to tame my Tele.
If I back the mids down to 5 with the treb. & bass it cleans up quite a bit.
I may also be the speaker change.

I think its possible, even likely that the bias has drifted after 5 years so I need to check that. I am feeling more confident after pulling the chassis for the speaker swap. I looked around in there and got the lay of the land. I need to get a meter and check the bias.

Thanks everyone for their suggestions...I even enjoyed the hijacks Crunchy! ;) :mrgreen:

Yep, bias shifts over time due to the component drift that I mentioned. Also, if your local power company has reduced the standard wall voltage by even a couple of volts, this can have a contributing effect.

If you want to pursue speaker changes, give this a look: webervst.com. He does amazing work in both ceramic and AlNiCo magnet structures. I use Ted's AlNiCo Blue Dogs exclusively.

[jazzrat]

Thanks Mike.
I have consided the Webers. They have a great special on some speakers
right now but I happened to have a nice Carvin 100 watt'er in hand. Prolly not as good as the Webers but looks very Celestion'ish with a huge magnet and very stiff frame. Certainly better than the stock Fender Eminence

[dmw]

I know I told you I'd be surprised if it was the speaker. I'm still surprised as they typically don't get "flabby" with that number of years of use. After all, I don't think you're a metal guy pushing your amp to the max over an extended period of years.

I dropped a hint to you at another board but Carvin's got their 12" speakers on sale for $19.95 (USA made by Eminence) last time I looked. I bought one as a spare when they were $29.95 as I thought that was a pretty good deal.

[jazzrat]

Yeah, I answered your post over there Dave. It may not be that the speaker is bad, just underated for the volume we are playing at.
The one I put in is a higher watt rating so I may be hearing some headroom there. I think the bias has drifted over time. i need to check that.

[Crunchyriff]

Jazzrat- Ditto the Webers. Ted make some fantastic speakers. FWIW, Next cab I buy is going to be chock full of Webers...

PRS24- I musta mistakenly thought I saw a pic you posted witha a boog in the background...sorry!

Marketing something as "STRxxx" sure sounds suspiciously like an attempt to associate with the historic Sylvania types, don't it?

Oh for the days of Sylvanias!!!

[Ravindave_3600]

OK, further adventures....
I took the amp in the local music store that I bought it from. These guys have good ears and years of experience with Fender amps.
He heard what I was hearing so at least I know it's not me. He did not think it was anything electrical. His suggestion was possibly an old speaker or a sympathetic chassis vibration.

When I got it home I tried all kinds of tube swaps just looking for something. I also swapped out the speaker for fun.
Conclusion: He suggested it and may be right...I am just pushing the amp in ways I never have before. I did notice one thing. I tend to run the mid-range pretty high and treble and bass down to tame my Tele.
If I back the mids down to 5 with the treb. & bass it cleans up quite a bit.
I may also be the speaker change.

I think its possible, even likely that the bias has drifted after 5 years so I need to check that. I am feeling more confident after pulling the chassis for the speaker swap. I looked around in there and got the lay of the land. I need to get a meter and check the bias.

Thanks everyone for their suggestions...I even enjoyed the hijacks Crunchy! ;) :mrgreen:

Glad the situation has gone from "frustrating" to "intriguing"!

[stephen]

When I got it home I tried all kinds of tube swaps just looking for something. I also swapped out the speaker for fun.
Conclusion: He suggested it and may be right...I am just pushing the amp in ways I never have before. I did notice one thing. I tend to run the mid-range pretty high and treble and bass down to tame my Tele.
If I back the mids down to 5 with the treb. & bass it cleans up quite a bit.
I may also be the speaker change.


OK, this is an interesting equation added to the mix! Maybe, what might fix it up rather than a lot of amp work, is maybe swap out the caps on the tone pots on your Tele to tone down the brightness, or maybe even different tone pots? I'm not sure of all the different cap values, but I'm sure someone here does, and can run you through some different types of variations, and there results. Just a thought, I could be wrong, but you never know!?!