TOS muddy with humbuckers

[67polara]

OK, I built the TOS and did a few mods.  I love it with my guitar, a 1967 Guild Polara.  I take my amp to a gig Weds and tell Gino Mateo how great the amp is and he says let me play it.  So He walks over and plugs in his 335, it sounded terrible!  Even the clean channel sounded over driven.  Very Muddy and bass heavy.  As a matter of fact he started to play the Blues and in mid song changed to Iron Man it was that bad.  He plugged my guitar in and said how sweet it sounded.   

What can I do to make it sound good on Humbuckers and yet change back with a flip of a switch to what I have?

Tony

[Tone Junkie]

A couple things you could do first try a 12ay7 in V1 also your first cathode cap its a 2.2 uf get a switching pot for your closest pot put a 1uf were the 2.2 is at, then put another 1uf on the pull switch  that way when your friend plays its 1uf when you play you pull the handle and its 2uf I had a problem with mine for one guitar it would be perfect for my other guitar it would be two bassy you have to put several things like your cathode caps on a pull switch to get the best of both worlds but try that first . this amp is very volume sensative and is tailered towards a lower gain pickup thats why with yours its dialed in perfect and when he came in with hotter pickups it wasnt the same. Im sure there are others here much more knowledgeable than I, with  better suggestions so wait till they chime in.
Thanks Bill

[jjasilli]

I have experienced humbuckers swamping the 1st preamp stage of some amp builds.  I.e., with standard issue dual Fender inputs, they like #2 (hi power source) better. That's a full 68K of Input Resistance.  Input Resistance is different from a grid stopper.  See www.aikenamps.com > tech info  The grid stopper defeats oscillation but provides no attenuation to input signal in the guitar's frequency range.  An input resistor yields attenuation of signal because it forms a voltage divider with the 1M grid leak resistor.  

Maybe move the 33K grid stopper to before the 1M grid leak.  An input resistor value of 10K - 120K should work.  Try to find a value that works for both single coil & humbucking pickups, probably 33K or 47K??  More complicated:  install hi-lo input jacks; or a SW.

EDIT:  tube swap is a good idea, but it might defeat overdrive capability.

[jojokeo]

Jjasilli is correct about creating input sensitivities to w/ different guitars but if it was me (and your amp is already built):
#1 - look at the yellow and red circled areas. The red will make the most and immediate difference by putting treble bleed caps on your 1M volume pots. You can make these controlled by a switch if you want to for different guitars/pickups/cable lengths, etc...
#2 - if you feel you need a bit more clarity earlier overall in your mix - put some bypass caps on the yellow areas as you're losing highs w/ these resistance areas also.

*I stopped using 1M pots for volume control in a lot of instances due to the fact the many times using this value isn't needed for this to the detriment of loss of highs and needing treble bleed caps to go w/ them more times than not. So I ask why use them in any place that calls for a simple vol control and go through that? Answer, stop doing it then  
There are times where you may want one to keep the loading down on the prior stage but this isn't always as often as one might think.

[tubenit]

So He walks over and plugs in his 335, it sounded terrible

It's NOT just the humbucker pickup. I play humbuckers thru my TOS and Tweed BluezMeister both and the tone is very clear, IMO and it cuts thru a mix of our band really well. I don't think either amp sounds at all muddy. The overdrive is a very clear tone to my ears. Others have offered me similar feedback about the TOS, TBM  and tone.

A few yrs ago, a Gibson semi-hollow body player came over and plugged into one of my amps. It didn't sound right. It was waaayy too dark thru one of my amps. However, I plugged my Tele with buckers in and it sounded super sweet & the player thought so also. This same guitarist used a Deluxe Reverb Re-issue and his amp and guitar were a good match for what he was doing.

The old Gibby amps were notoriously bright in some cases. HotBluePlates (who worked for Gibson) commented those amps were voiced bright because of how dark the Gibson guitars were.

I typically voice my amps to emphasize the mids more. Geezer seems to have somewhat brighter sounding amps than mine, perhaps?

Now I know Larry Carlton uses a 335 in a Dumble amp. However, my understanding is that he seldom uses the OD channel?  I also heard that his OD channel had one instead of two gain stages?  I don't know if either of those statements are fact or not?  I will also say that LC's tone does sound muddy to me when his OD is cranked such as on the Renegade Gentleman and Fretwire CD's. I don't care for that tone.  I strongly prefer his tone playing with the band FourPlay.

I do know from LC's website video that he intentionally sets his amp and guitar volume up to where the amp hangs right on that edge of breaking up.

The James tone stack on the OD section could be something of a factor?  You might consider playing with the values in that (per Duncan Tone Stack Calculator or changing it out for a 5E3 type tone control.

Just my two cents worth.   Best regards, Tubenit

[jojokeo]

Hi tubenit! I really admire yours and Geezer's "product support" and time that you give others especially when it comes to one of your amps. 

[tubenit]

Two other things you could experiment with.

Try a 12AT7 in the LTPI & a 5751 in V1.

Try a 8uf/100v to 47uf/50v range  with the power tube cathode instead of the 150uf cap. 

I have had a spst switch on power tube cathodes before switching in a larger cap to parallel a smaller one.

With respect, Tubenit

[67polara]

I do have a hi lo switch for input I will try the mods you recommend and and see what works best I just don't have his guitar here so it may be a crap shoot.  I could never get the break up with my guitar at any volume.  I am so proud of this amp but with in 3 cords my heart broke.  Especially with a semi Famous guitar player playing it.

Tony

[Willabe]

Yeah, but he said how sweet it sounded with your guitar!

No big deal, not all guitars sound great through all amps. Different tools for different jobs.

It's your amp which you built for/to go with your guitar and it sounds great to you and him when paired together.

No reason for heart break, IMO you should still be proud of your work. You did what you set out to do with this build. Now maybe just take it a little further and add some player options like the guys have mentioned.       


           Brad                       (I love these new little guys)   

[jjasilli]

I do have a hi lo switch for input I will try the mods you recommend and and see what works best I just don't have his guitar here so it may be a crap shoot.  I could never get the break up with my guitar at any volume.  I am so proud of this amp but with in 3 cords my heart broke.  Especially with a semi Famous guitar player playing it. Tony

Without the guitar you can use a signal generator, electronic guitar tuner output, even a cassette deck, etc.  Measure the AC voltage of the signal fed into the amp.  Compare it to to a guitar's output.  Figure 200mV for single coil; 500 - 800mV for humbuckers.

Maybe measure the output of your guitar too.  

[Tone Junkie]

jojokeo anyway to put that file into a .gif so its easy to open.
Thanks Bill

[jojokeo]

Sure Bill. The red circles are what I'd do first. They'll make a bigger difference over any tube or other changes for what's described and wanted, the yellow ones shouldn't be done until after seeing how the red-circled ones perform.

[67polara]

OK, I'm stupid what size cap and where?

Tony

[tubenit]

Try between 47p and 120p with wire and alligator clips and see what sounds best to your ears FIRST and then solder it in .

With respect, Tubenit

[Tone Junkie]

jojokeo I didnt need it for mine, but I knew I would learn something about the circuit.
Thank you Bill

[67polara]

From what point to what point do I install this capacitor.  Does it go across the volume pot or where?

[jojokeo]

Here's a quick little drawing. Looking at the back of the pot w/ the lugs pointing upwards lug #1 is on the right where the signal usually goes in, lug #2 or middle is where the signal goes out of the pot and lug #3 on the far left is grounded.

[Willabe]

Yes, if it's a treble bypass cap. One end of the cap to the pots input and the other end to the wiper.

That way the highs bypass/go around the pots resistance, but the more the pot is turned up the less there is to bypass. So the more the amp is turned up, the less you'll hear it. It works but not evenly across the rotation of the pot.  

Which is why (at least 1 reason) the guys also brought up making the cathode bypass cap/s smaller. That will strip out some of bass at any volume setting, which in turn would leave more treble to balance against the bass.


                   Brad              

[67polara]

Thank you that is what I thought just wanted to make sure we were on the same page.

Tony

[Tone Junkie]

Tony the reason I like changing the cathode bypass caps is I can use that pushpull pot and switch it in and out you just put a 100k underneath it so it doesnt pop when its being switched, because If you have it dialed in for your guitar you want to make it switchable to stay were you have it now.
I have never tried a treble bypass cap on a switch for the volume pot but I see old fender designs If I remember right that put it on a bright switch which would also be an excellent way to go, because as I stated before you always want to be able to get back to the sound you have now. Plus if you dont have a guitar with that type of pickup to use in testing no matter what you do your shooting blind

Thanks Bill
PS. sorry I talk to much, time to get back to building my soldering iron is hot.  
                                                  
                                        gotta love these things

[67polara]

Good enough I will try the pull pot and the cap first.  Should I do it on the OD channel also?  After thinking about it for a while I think When I was letting him use the amp I should have turned the fatness control off also.  I didn't even think about it but I keep that control all the way up all the time.  With my single coils it adds bite to the sound but I think with his Humbuckers it just went into overdrive for the next stage.  I did change out the 12Ax7 for a 12Ay7 and it lowered the power considerably.  It still sounds good if not better just have to turn it up a bit more.

Tony

[tubenit]

When I was letting him use the amp I should have turned the fatness control off also

I agree with that!  The 335 needs a brighter and thinner tone from the amp.

And I would have dialed down the trim into the OD, and lowered the drive setting and increased the level setting to compensate.

With respect, Tubenit

[Geezer]

When I was letting him use the amp I should have turned the fatness control off also

I agree with that!  The 335 needs a brighter and thinner tone from the amp.

And I would have dialed down the trim into the OD, and lowered the drive setting and increased the level setting to compensate.

With respect, Tubenit

+1 too all that........adjustments must be made to the amp controls for different guitars. These amps are very sensitive to changes to the input (pickups, pedals, etc)

G

[Tone Junkie]

Thats one of the things I love about the amp you just dial down the volume knob and you have a whole new sound but having that type of sensativity has a cost, Geezer just said it all right above this one

[bigdaddy]

As someone who has used many ES-334/345/355 guitars for many years, since the 70s, they are funny guitars. Because they are semi hollow they produce enormous amounts of lows and mids. That's why they sound best with low output PAF type pickups, IMO. If you look at Freddie King's later ES355 the bridge pickup is screwed down on the wound strings. I have found that to be necessary if the amp puts out a lot of lows, he was using new SF Fender Quad, Twins, Super Six amps at that time. You just get a howling  sound if you crank the amp with those guitars, you have to turn the bass down.

One of my favorite guitars was a cherry ES335 1999 with a pair of Tom Holmes pups, I had 2, one was a 2000. They were brand new and my main gigging guitars. Those sounded great through my BF Fender clones but the bass was down on the amps, way down. As your volume goes up on a fender tone stack your bass must come down, much more so on the ES models. Use a high output pickup on the ES335 and you really have to drop them down from the strings. A 7K range PAF would be perfect for the neck for instance and as loud as a Les Paul with an 8K neck, averaged out.