TOS & TBM tweak

[tubenit]

I am curious about something?  I've found a tweak that worked really great on both my Tweed BluezMeister and Tweed Overdrive.

I'd like to share the tweak with someone who has built the TBM or TOS (and will try it) & get feedback on what it changed in their amp to see if you're getting the same results as I am getting. I feel like it is a signficant improvement.

IF you've built a TBM or TOS & want to try the tweak and post the results and your impressions, I would like to share what I've done in a PM to you.  I want to see if this is unique to my two amps or will work on anyone's TBM or TOS build?

And I don't want to describe the tonal improvement to you first. I'd like to see how you describe it to see if the results are indeed the same as what I am hearing. This is turning out to be kind of like my "secret sauce" on these two amps.

I feel like it's worth trying and it's pretty simple, so if you're up for trying this.  Just post that you've built one of those amps & I'll PM you the tweak.

I promise to share it with the entire forum after getting some feedback.

With respect, Tubenit

[Tone Junkie]

Tubnit I have the TBM right now and would give it a shot I was also thinking of trying that dumble local feedback thing.
Thanks Bill

PS unfortunatly the TOS is now the TBM I took a page out of your book wish I had them both to play side by side

[tubenit]

OK, I sent a PM to both Tone Junkie and Firemedic with the tweak info .  Anybody else want to try this that has the TOS or TBM amp?

I'm trying to see if everyone ends up with the same positive results and similar descriptions of the tone change.  Again, this could be unique to my amps, but I'm hoping and thinking it will produce similar results with similar topology.

With respect, Tubenit

[triode]

Why don't you show us the change on a schematic without telling us what it did to the tone?

Just asking... at one time I took one of your designs and changed it up quite a bit. I think it is
the TOS. I would be curious to see what you did and compare... I will have to go back and
look through my files.

[William_G]

Tubenit I will give your new tweak a try. I did you last mods on my TOS and posted that it made a big improvement in the overdrive. I do not post a lot, but I do enjoy reading and learning from this forum.

Thanks, William_G

[TIMBO]

Hi Guys, I promised myself that i was going to start concentrating on some  but i guess some more  i mean tweaking can't hert. So count me in. Thanks


My schem below

[tubenit]

William G and Timbo, ...... I sent you both a PM with the tweak information. If you try it, just post whatever results you get. Whether good or not good results, just be authentic with what you hear on your amp.

OK, we've got 4 amps besides my two that we'll try this on. That ought to give us a reasonable "test".   I am sure hoping others get similar positive results as mine.

Triode, I am committed to posting the schematic for the forum. To the best of my memory, I've shared every design and tweak that seemed to my ears to be a reasonable or great idea. The forum members have been extraordinarily generous to me, so I feel sharing is just returning the many favors.

There is a reason I am choosing this approach this time. There is nothing new in this tweak idea, it's just that the results were such a significant improvement in tone for me that I am puzzled why it works so well and curious if others will get the same results.

With respect, Tubenit

[tubenit]

Timbo,

BTW, I dropped down from a 150uf cathode cap to 10uf cathode cap on the power tube cathodes.  I find that it is a smoother tone for me. In an ideal world, I'd like something a little less than a 150uf on the clean channel but have it switched to a 10uf when the OD kicks in. IF you haven't tried that, you might give it a shot.

with respect, Tubenit

[triode]

Ok. I also realized I did not use the TOS/TMB either. I think I saw that design and went and built something else
on an idea I had. I suppose I need to build one once to check it out. 

Thanks.

[tubenit]

Triode,

I sent you a PM.   Tubenit

[William_G]

Tubenit,
I got your PM message with the TOS tweaks and gave them a try on my TOS with reverb. First I clipped the cap on the OD trim control and this brightened the overdrive quite a bit. Next I clipped the cap on the OD drive control and this did not brighten the overdrive as much this time, but still brighter then without the cap.The last thing, I clipped the cap on the OD level control this made a very big change in the overall tone. The tone control now has better difinition then it did without the cap. This IMO gave the amp a even better overall sound when in the overdrive channel and I though it sounded great before the tweak.
Thank You Tubenit for yet another great tweak to this fantastic amp!!!!!!
My amp is very close to Tubenit layout, but my amp is forty watts with JJ 6L6'S. I run the preamp boost on low setting for my Les Paul and medium for my Strat. If you have not built one off these amps yet, you should build one!!!!

Willam_G

[jojokeo]

Initial thoughts (w/out knowing what this is about) reminds me of the "smoothing caps robbing tone" comments a little while back? Where in the quest for "smoother" and less brittle or buzzy overdrive can also be easily overdone and then takes away the guitar's clarity & voice characteristics with it. Not that this may be "bad" but some people like a dark tone and some like clearer or brighter.

[tubenit]

William_G,

THANKS for posting your results!

made a very big change in the overall tone & gave the overdrive an even better overall sound

How would you describe that it made it "better" overdrive tone. Which two descriptors of these would describe the change that you heard the most?  There is NOT a "correct" answer. Again, I'm simply trying to see if others get similar or different results.

sustain
touch sensitivity
definition
blooming
harmonics
brightness

I'll post the tweak & schematic after hearing back from one other forum guy.

With respect, Tubenit

[William_G]

Tubenit,

[/quote]
How would you describe that it made it "better" overdrive tone. Which two descriptors of these would describe the change that you heard the most? 

Definitition & Brightness is what I heard in the full range of the tone control. The cap improved the tone control overall range too my ears, it is a little brighter or not as dark as without the cap. The definition of the tone control now has a wider tone range to my ears. The amp already had good sustain, touch sensitity, blooming and good harmonics IMO. I hope this defines the tweak a little better.

Thanks, William_G

[TIMBO]

Hi guy's, I added the cap in the three different positions but i would have to say that i am unable to give much of an opinion, i cant say that it made much of a difference but that may not be the case of other amps.

I have not played my TOS for some time and had forgotten what i had done (added mods to the schem supplied ) wonce plugged in it came flooding back.

HI/ LO - switch needs on explanation.
CLEAN - Very nice Tweed
OVER DRIVE - Tweed on steroids

Added Mods
TWEED SWITCH off - Clean mode
TWEED SWITCH on - The thing is out of control ( in a good way)

V1 CATHODE SWITCH - A combo of different values
V3 CATHODE SWITCH - A combo of different values

At the end of the day i was always more than happy to be able to construct the TOS and greatful to Tubenit & Co. for this outstanding amp.
I need to get time to play it more because it has so many voices to choose from.
Thanks again

[tubenit]

Guys,

Thanks for trying the tweak out. On my two amps, it did exactly the same thing on both of them & it significantly increased the blooming and harmonics for some reason.

I tried numerous small caps first on the OD trim, then OD drive and then OD level which has my psuedo 5E3 tone stack. On the OD trim and the OD drive, it simply increased highs but did NOT increase blooming at all.

I found a 120p silver mica on the TOS was best and on the TBM, I felt like a 100p ceramic gave the best tone.

It was really easy to A/B the cap on or not on and hear the difference in blooming. The notes would swell considerably more and the harmonics were more pronounced and sweeter.

In the same way a Tube Screamer changes overdrive when on .......... the cap across the OD level increased the blooming.

I would guess there are differences in our amps in some regards with speaker, tweaks, voltages and guitars being used?

Having said that, since it did the same thing with both of my amps, I thought it might work on anyone's? But it doesn't sound like it does?  

I appreciate you guys trying it out. Timbo, it sounded like it did nothing for your amp but William_G, it sounds like it improved tone for you.

I am wondering if your using the actual 5E3 tone stack and not the psuedo 5E3 tone stack? And I am wondering if that would make a difference?

The other thing I am wondering is if you guys are still using the 150uf cathode cap on the power tubes. I also found out a couple of months ago (?) that a 10uf cathode cap allowed for more blooming and the stiffer 150uf cap diminished blooming?

With respect, Tubenit

[tubenit]

Well, I looked at the 5E3 tone stack and the psuedo 5E3 tone stack and there is a difference.

Also I noted on Timbo's OD level that he uses a 1M pot vs. the 250k which is a significant difference because with the 250k there is less resistance in the signal path.

Don't know if those factors could possibly account for the difference in results?  Guys, any thoughts on that?

With respect, Tubenit

[William_G]

Tubenit,

My TOS is close to your amp with three small changes, on the clean tone stack I have a 49K res. not a 100k trim. I have
no OD boost switch and I have a 47uf cathode cap on the power tubes. I will test today with a different speaker, a WGS
12" g12c, their version of Jensen c12n. That speaker has a greater range than the 12" Veteran 30, their version of a Celestion Vintage 30 that I did the first test on your tweaks. I will let you know my findings with the different speaker.

Thanks, William G

[tubenit]

Cool!  Look forward to the review. Thanks for sharing the information and contributing to the forum.

With respect, Tubenit

[jojokeo]

Thanks for trying the tweak out. On my two amps, it did exactly the same thing on both of them & it significantly increased the blooming and harmonics for some reason.

IMHO it makes total sense; you're letting your highs and higher mids part of the signal through the pot's resistances unimpeded (when the control is adjusted at anything less than full up) = less loss of tone and improved clarity and harmonics as well as a stronger signal for everything above that cap's shelf frequency = improvements noticed.

Well, I looked at the 5E3 tone stack and the psuedo 5E3 tone stack and there is a difference.

Also I noted on Timbo's OD level that he uses a 1M pot vs. the 250k which is a significant difference because with the 250k there is less resistance in the signal path.

Don't know if those factors could possibly account for the difference in results?  Guys, any thoughts on that?

Yes, the different values do make a difference on the effects. Also I was going to point out your two differnt pot values for the two controls in your two amps and you also have that high value resistor in front of the two controls on the TBM which removes highs before it even reaches your tone/drive or vol controls. It's going to have a similar affect like a slope resistor in a normal tone stack. The other differences btwn your two particular amps is that you have a diff frequency response set up btwn the two. So filtering/controls w/ not be the same as your signal outputs are not the same.

Just my .02 tubenit
regards, Keo

[Tone Junkie]

Ok finally got a few minutes alone so I could try it . what I noticed is it brightened it up a little in a good way, my blooming wasnt magnified but it added to my harmonics.
It had great harmonics already but kind of added some extra to it, hard to explain the harmonics where a bit brighter because of the first change but it had like an extra couple it didnt have before, I will definately keep this. thanks Tubenit
I have the cut control in Geezers schematic not the tonestack that tubnit has I have got used to this one not enough time to change it around and try it that.
Thanks Bill

[Tone Junkie]

Ok now that I read jojokeo,s explination, what he said

[William_G]

Tubenit,

The 12" g12c made a big difference in the sound clarity of my TOS amp.I put the cap on a switch, I could here a big
difference in the blooming & harmonics with the cap on. The note difinition is clearer with the cap on as well. The overdrive has blooming & harmonics with out the cap, but they are not as eazy to here IMO. I also changed the cathode
cap to 10uf from the 47uf, I put these on a switch and the amp did sound better with the 10uf. This tweak brought the
blooming & harmonics on equal with the clean channel IMO. The right speaker makes a huge difference in the way this amp sounds as well as most amps. Thanks again to Tubenit & Co for this great amp!!!!!!!

Thanks, William G

[tubenit]

IMHO it makes total sense; you're letting your highs and higher mids part of the signal through the pot's resistances unimpeded (when the control is adjusted at anything less than full up) = less loss of tone and improved clarity and harmonics as well as a stronger signal for everything above that cap's shelf frequency = improvements noticed.

That makes sense to me, but I am puzzled why the bright cap on the OD trim and OD drive did NOTHING to improve the overdrive, it just made it brighter sounding  VS. the increased blooming and harmonics on the OD level?

it brightened it up a little in a good way, my blooming wasnt magnified but it added to my harmonics.

I could hear a big difference in the blooming & harmonics with the cap on.

ToneJunkie and William_G, it sounds like both of you got good results from the tweak in some form or fashion whether harmonics, tone in general or blooming.  Good show!  Glad to hear it made a difference that you liked.

with respect, Tubenit

[Willabe]

[That makes sense to me, but I am puzzled why the bright cap on the OD trim and OD drive did NOTHING to improve the overdrive, it just made it brighter sounding  VS. the increased blooming and harmonics on the OD level?

Maybe last in line? Last gain stage opened it back up with it's extra gain, to free it up to "breath" after being squashed by the in series resistors before ?  


      Brad      

[jojokeo]

That makes sense to me, but I am puzzled why the bright cap on the OD trim and OD drive did NOTHING to improve the overdrive, it just made it brighter sounding  VS. the increased blooming and harmonics on the OD level?

I think Willabe's point is valid in that the output from the gain stages will make the most dramatic & audible difference.

Why? 1st - things happen to the input signal when being amplified by way of where it's load point is set and w/ it's biasing towards cut off or grid current limiting which introduces various even and/or odd orders of harmonics along w/ the notes' fundamental frequencies. 2nd - on both of your OD gain stages you are in fact brightening the input signal w/ those treble bleed caps (prior to each gain stage respectively). At the same time with you're smoothing capacitors on the load resitors and also the treble feedback resistors AFTER both gain stages are dumping the high end frequencies and harmonics that you just created and tried to increase and amplify. So, the net affect and end result of each stage is ruled by the treatment of the signal outputs. You're dumping the high end frequency and harmonic signal content from those stages that you earlier tried to create and/or preserve.