Overtone 100w, up and running, reporting voltages...

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massygt6
Posts: 168
Joined: Thu Feb 16, 2006 12:49 pm

Overtone 100w, up and running, reporting voltages...

Post by massygt6 »

Hi guys,
please take a look at the voltages I've in my clone...

v1

pin1 199v
pin3 1,9v
pin6 206v
pin8 1,75v

V2

pin1 215v
pin3 1,74v
pin6 216v
pin8 1,75v

v3 (PI)

pin1 316v
pin3 60v
pin6 312
pin7 38v

POWER TUBES

B+ 463volts
biased at 35 mA

they seems ok, except for the PI, aren't they a bit on the high side?
I found the clean channel gorgeous with my strat and es335, but the OD channel is not what I've expected, not entirely almost...
Many of you posted great clips, super smooth and refined sounds, at a first listen I'm still a bit far from that kind of sound.
I'd like to get a smoother sound out of the od channel, less middy...mine is a NON HRM version...so wich direction I should take first?

1) snubbers
2) HRM mod (in this case I see that every hrm amp has no subbers)
2) lower the preamp voltages?

Second question, is it worth to try some EL34 in there?
thanks
Max
dogears
Posts: 1902
Joined: Wed Feb 01, 2006 1:29 pm

Re: Overtone 100w, up and running, reporting voltages...

Post by dogears »

Max,

You could try increasing the dropping resistor to the PI by 1K.

Also, your V1B cathode voltage seems low relative to the plate. Try swapping tubes.

Try these two changes first. This will restore the build to a Dumble baseline.

1) Raise the 150K feeding the OD trimmer to a 220K (as in almost ALL Dumbles.)
2) Raise the bypass cap on V2B to a 4.7uf from 2.2uf

Good luck!
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tsl602000
Posts: 103
Joined: Sat Mar 03, 2007 10:47 am
Location: Netherlands

Re: Overtone 100w, up and running, reporting voltages...

Post by tsl602000 »

Max,
I'm a strat player too and the biggest improvement I got was when I took a 330K and .01 cap from OD2 plate to ground and put a 10pF cap over the master volume.
I read this somewhere and think this mod came from Dogears. All the credits to him..
massygt6
Posts: 168
Joined: Thu Feb 16, 2006 12:49 pm

Re: Overtone 100w, up and running, reporting voltages...

Post by massygt6 »

Thanks!!!
Your advise is gold for me, since you got one of the most beautiful tone around!
I'll try these mods and report back...
thanks again...
Max
massygt6
Posts: 168
Joined: Thu Feb 16, 2006 12:49 pm

Re: Overtone 100w, up and running, reporting voltages...

Post by massygt6 »

tsl602000 wrote:Max,
I'm a strat player too and the biggest improvement I got was when I took a 330K and .01 cap from OD2 plate to ground and put a 10pF cap over the master volume.
I read this somewhere and think this mod came from Dogears. All the credits to him..
So thank you too, and double thanks to dogears ;-)

the 330k and .01 cap, you mean in series from the plate to ground? like this...

od2 plate-----330k-----(.01)------ground

on the master volume, now I've got a 15pf...a 10pf will do difference? is such a small change!
dogears
Posts: 1902
Joined: Wed Feb 01, 2006 1:29 pm

Re: Overtone 100w, up and running, reporting voltages...

Post by dogears »

Even a small change in bright cap is very noticeable!

I use a .001uf to ground. Not .01uf

Thanks to Gil....

;)
massygt6 wrote:
tsl602000 wrote:Max,
I'm a strat player too and the biggest improvement I got was when I took a 330K and .01 cap from OD2 plate to ground and put a 10pF cap over the master volume.
I read this somewhere and think this mod came from Dogears. All the credits to him..
So thank you too, and double thanks to dogears ;-)

the 330k and .01 cap, you mean in series from the plate to ground? like this...

od2 plate-----330k-----(.01)------ground

on the master volume, now I've got a 15pf...a 10pf will do difference? is such a small change!
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dobbhill
Posts: 434
Joined: Sat Jan 22, 2005 12:04 am
Location: Louisiana

Re: Overtone 100w, up and running, reporting voltages...

Post by dobbhill »

I would put the .001 first to keep the voltage off the 330k, but that's just me. It should sound the same, yes?
D
There are no stupid questions, just stupid people.......
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odourboy
Posts: 796
Joined: Fri Apr 27, 2007 4:07 pm
Contact:

Re: Overtone 100w, up and running, reporting voltages...

Post by odourboy »

Is this different from the post-OD treble bleed mod Gil uses (which I believe is a 250K trimmer to a .001 to ground before the 'ratio' pot)?
"Let's face it, the non HRMs are easier to play, there, I've said it." - Gil Ayan... AND HE"S IN GOOD COMPANY!

Black chassis' availble: http://cepedals.com/Dumble-Style-Chassis.html
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tsl602000
Posts: 103
Joined: Sat Mar 03, 2007 10:47 am
Location: Netherlands

Re: Overtone 100w, up and running, reporting voltages...

Post by tsl602000 »

dogears wrote: I use a .001uf to ground. Not .01uf
ouch.. that's what I meant
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Structo
Posts: 15446
Joined: Wed Oct 17, 2007 1:01 am
Location: Oregon

Re: Overtone 100w, up and running, reporting voltages...

Post by Structo »

I'm a strat player too and the biggest improvement I got was when I took a 330K and .001 cap from OD2 plate to ground and put a 10pF cap over the master volume.


So how is that implemented?
The .001uf and resistor?
Tom

Don't let that smoke out!
massygt6
Posts: 168
Joined: Thu Feb 16, 2006 12:49 pm

Re: Overtone 100w, up and running, reporting voltages...

Post by massygt6 »

dogears wrote:Even a small change in bright cap is very noticeable!

I use a .001uf to ground. Not .01uf

Thanks to Gil....

;)
massygt6 wrote:
tsl602000 wrote:Max,
I'm a strat player too and the biggest improvement I got was when I took a 330K and .01 cap from OD2 plate to ground and put a 10pF cap over the master volume.
I read this somewhere and think this mod came from Dogears. All the credits to him..
So thank you too, and double thanks to dogears ;-)

the 330k and .01 cap, you mean in series from the plate to ground? like this...

od2 plate-----330k-----(.01)------ground

on the master volume, now I've got a 15pf...a 10pf will do difference? is such a small change!
ok, got it ;-)
by the way, raised the feed trimmer resistor to 220k, v2b cathode bypass is now 4,7uF...wow! what a difference!
The buzz is almost gone, and the sound is a lot smoother!
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