trinityamps.com

That's going away from that specific Dave Reeves' preamp design, but there were also some early Hiwatt preamps that had 220k/2k2 on the stage in front of the tone stack, although they also had a big cathode bypass cap on the first stage for more gain. However, that seems like a nice alternative variation which maybe we could add to the tweaker notes.


There isn't any cathode resistor of that value. So I'm not too sure what you're doing there, or how it would make the amp cleaner. Just be aware that changing resistor values on V3 will probably affect the PI bias voltage, since they're DC coupled. This voltage is set by a pair of grid resistors, which in early Hiwatt amps are generally either 1.8M/1M or 1M/560k. I chose the latter version for lower noise levels.


It may help to keep in mind that the Overdrive control only sets the *output* level from the Overdrive/OL stage, while the stage's gain/distortion level is actually set by the Normal/Bright pots. So the simple answer to your quest is to increase the Normal/Bright controls to hit the Overdrive stage harder, while also reducing the Overdrive pot's level.

HTH

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DOH! I meant the grids.... It was late! Yeah, I was copying the early DR schematic.

I wondered if that wasn't what you meant. Now here's the thing - if you change the value of one of the resistors in that pair you have to change the other one too, or the PI's bias voltage will end up out of whack. There is also going to be zero difference in gain when you change these resistors since they are bypass by a 0.022uF coupling cap. Those resistors are only there for DC purposes not signal. So I doubt you will get much benefit from changing them, plus you will get a slight increase in noise.

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Great tones come in small glass jars!

It's now back to "stock" triwatt specs...... My isues were in the way I wired the "link" switch. It was loading down the guitar too much, so I removed it and have completely separate inputs, like a 2 holer. MUCH better.

I am still wondering what's going on with my bias. I reinstalled the 6V6s, and now can only get 23 with the pot maxed out. I was able to get it up into the high 20s, and I haven't changed anything on that side of the amp at all... Well, now that I think of it, I did tap into the bias supply to power my FX loop PS.

Off to remove it and see if I get my bias control back......

That very same thing happened to me. I re-flowed the joins in the bias supply & it was fine. I think it was a ground, but I don't know for sure.

That DG linked input is a real tricky one to get wired correctly. And even when you get it right, you need to remember that you then have two 1M resistors and two 68k paralleled at the preamp inputs. So the loading will be a little different. FYI Pete Cornish also did an alternative version (supposedly not used by Dave Gilmour) that keeps the 1M input loading - http://mhuss.com/Hiwatt/Schematics/DR_P ... put_v2.pdf However, the original v1 sounds great to my ears, and if it was good enough for DG, it's good enough for me.

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Great tones come in small glass jars!

I saw that 2m2 setup, and was thinking that I might try that on my 4 holer clone, just for grins. I generally don't like the sound of my guitars into my Hiwatts with a lot of impedance between the pickup and amp. I found that with a lot of unbuffered pedals, my JP would get kind of farty sounding, especially the low e string. My Triwatt did the same thing with my link switch, and it got worse with a few pedals in front of it.

Dave G was mainly a Strat player, so I guess the added input loading worked for him. With P90s or buckers, I didn't like it.

I think DG also mostly played through a couple of pedals in front of the amp, if we're to believe what we're told. However, in studio tests with the Triwatt we threw just about every kind of guitar and pickup under the sun at it, and it appeared to love them all.

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Great tones come in small glass jars!

It might be a Strat Thing?
It might the buffered thing?
Or a little of both!

I'm running my Triwatt in the "Linked Mode", with 6V6 Tubes, & it seemed a lot less "farty" than some Twin Reverbs (running straight cable) I've A/B'd. The Triwatt seems to be one of the "tightest" amps I have ever played.

My current effects chain is below, and it should be all "True Bypass" except the EMMA OnoMATOpoeia which is buffered:

Stratocaster/BBE Orange Compressor / Korg Pitchblack Tuner / Fulltone Ultimate Octave Fuzz / Voodoo Lab Micro Vibe / Fulltone Fulldrive II / EMMA OnoMATOpoeia / EHX Holy Stain (for Reverb) / BYOC Digital Delay / Triwatt 1-12 Combo w/BBQ Axis Ceramic Speaker & Avatar 1-12 Open Back Vintage Extention Cabinet w/Fane AX12-150 Speaker.

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ROB

I've found that I need at least one buffered pedal in the chain or I'll get the fartiness. I am in the midst of a pedalboard "revolution", so things are about to change, but traditionally, I've used:


A modded Vox 847 wah-> TB tuner (currently a Turbo Tuner) -> Barber Tone Press -> Light OD (Was a Tim, but now back to a Barber LTD) -> Keeley modded Rat -> Analogman Chorus -> Delay (currently a DL-8) -> MI Audio Boot N'Buff (for lead boost/buffering purposes) -> Amp (almost always a Hiwatt, sometimes a Marwatt, SF Twin, Traynor YBA1 or YCV50).

When I built my JP Hiwatt, I eliminated the Boost N'Buff (taking the only buffered pedal out of the chain) to use the built in boost and got the fartiness. The same with the Triwatt.

On all but the JP (which has only one input), I link the channels, which should be the same as the original (1M/68K) DG mod, right?


Santa is bringing me a Line 6 M13, so I am rethinking my board. Right now I predict that the only things left on my board will be an expression pedal, my LTD and the Rat. Oh, and a DI box for my acoustic.

No buffers in this pedal
Latest project... in case I get myself a Triwatt one of these days!


Joe G

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Joe, I have an old Wah pedal converted to a volume pedal which I rarely use. I'd love to add a nice-sounding wah circuit. Is yours commercially available as a kit, or did you design your own circuit and acquire your own components?

Hi Jim!
This wah is an old Dallas Arbiter pedal that I've had for about 35 years (see the other pics on Photobucket). The pot broke and it's been in a junk box since the late 70's. Everything is new now except for the case and the original Fasel equipped board. I had forgotten how noisy these things were, but it works great, true bypass added plus a few other mods.
I'm thinking of building myself a fixed wah with more modern appointments, buffered in and out, better resistors and caps, ac power option, LED's everywhere, etc.
Tonepad has bare boards or artwork to etch your own for wahs and many other pedals.
http://www.tonepad.com/default.asp

Small Bear and/or Tubes and More have all the parts.

Next up from the junk box are a "Ram's Head" Big Muff and an old Electric Mistress

Joe G

_________________
Some assembly required,
Brain sold separately...