Search found 234 matches

by rock_mumbles
Mon May 19, 2014 5:53 am
Forum: Trainwreck Discussion
Topic: Troubleshooting request for 15 watt LP PCB build
Replies: 35
Views: 5682

Re: Troubleshooting request for 15 watt LP PCB build

If you look at rj's picture, it looks to me like the presence pot wiring is the wiring for the Express presence control with a 5k pot not the wiring for the Liverpool presence with 25k pot
by rock_mumbles
Fri May 16, 2014 12:33 am
Forum: Technical Discussion
Topic: Combining capacitors in series and parallel
Replies: 16
Views: 5642

Re: Combining capacitors in series and parallel

That's fine just a lot of caps ... use load balancing resistors on the series caps
by rock_mumbles
Thu May 15, 2014 1:12 am
Forum: Trainwreck Discussion
Topic: Problem with startup
Replies: 33
Views: 3478

Re: Problem with startup

You need to hook up the bias pot as a variable resistor, with an outer lug and wiper connected together to the caps and the other outer lug to the resistor ...
by rock_mumbles
Sun Apr 20, 2014 4:34 am
Forum: Fender Discussion
Topic: Fender champ 600 no sound
Replies: 8
Views: 1924

Re: Fender champ 600 no sound

The 6V6 cathode resistor (R10 470 ohm 2W) is undersized and can burn out
by rock_mumbles
Sat Apr 19, 2014 5:18 pm
Forum: Technical Discussion
Topic: Swapping Tone Stacks
Replies: 5
Views: 1295

Re: Swapping Tone Stacks

If you take a 6G2 Princeton and keep the tremolo you'll end up with a really, really clean amp if you add a TMB tone control ... basically you are building a (AA964) blackface Princeton with a mid control ... If you want the amp to have some dirt, the TMB tone control needs a gain recovery stage aft...
by rock_mumbles
Sat Apr 19, 2014 7:51 am
Forum: Technical Discussion
Topic: Supro 1624
Replies: 4
Views: 1362

Re: Supro 1624

I built an SE EL84 variation ... it was really dark and really dirty Without the tremolo circuit, the tremolo channel input cathode is messed up. The 1.5k cathode resistor bypassed with the 35uf cap is supposed to be shared by two triodes ... for a single triode the resistor should be twice the valu...
by rock_mumbles
Fri Apr 18, 2014 3:14 am
Forum: Technical Discussion
Topic: tube substitution for preventing pre amp distortion. VHT AMP
Replies: 5
Views: 985

Re: tube substitution for preventing pre amp distortion. VHT AMP

Are you running the power control on full?

There should be no preamp fuzz with the power control on full power ...
by rock_mumbles
Thu Apr 17, 2014 12:44 am
Forum: Technical Discussion
Topic: tube substitution for preventing pre amp distortion. VHT AMP
Replies: 5
Views: 985

Re: tube substitution for preventing pre amp distortion. VHT AMP

What kind of guitar/pickups are you using? I first started reading your post and immediately I thought 12AY7 ... ... Using the clean input, Power control on full power, Boost off, and maybe guitar volume backed off, the amp should be clean My brother has both the Special 6 and the Ultra 6 ... I know...
by rock_mumbles
Wed Apr 16, 2014 11:52 pm
Forum: Technical Discussion
Topic: Just joined looking for tech help
Replies: 19
Views: 6849

Re: Just joined looking for tech help

I don't think it's so much you've ruffled feathers ... it's just being realistic. Where are you planning on putting the reverb tank? - I don't see any place in the cabinet where you could put in even a small reverb tank ... the top of the cabinet has the preamp/controls chassis and the bottom of the...
by rock_mumbles
Tue Apr 15, 2014 2:55 am
Forum: Technical Discussion
Topic: Just joined looking for tech help
Replies: 19
Views: 6849

Re: Just joined looking for tech help

... I also forgot to explain the unused v2a. I am not sure how to do it yet, but I want to put it on a switch. So it can be added as an extra gain stage in case I want more dirt. The end result I'm going for is a 10-15 watt non-master clean-ish kinda thing. I like the Excelsior, but want more out o...
by rock_mumbles
Tue Apr 15, 2014 2:49 am
Forum: Technical Discussion
Topic: Just joined looking for tech help
Replies: 19
Views: 6849

Re: Just joined looking for tech help

debug post

Sorry I didn't refresh so I didn't see that it had posted ...
by rock_mumbles
Mon Apr 14, 2014 11:12 pm
Forum: Technical Discussion
Topic: Just joined looking for tech help
Replies: 19
Views: 6849

Re: Just joined looking for tech help

What kind of Dumble amp are you thinking about? I don't see the Excelsior a good starting point for a D-style amp ... Excelsior to Princeton ... yes! A low wattage Small Special would work ... but the cathodyne phase inverter in the Excelsior will be something you'll have to work around For an ODS, ...
by rock_mumbles
Mon Apr 14, 2014 3:52 pm
Forum: Technical Discussion
Topic: 1970s Ampeg SVT refurb
Replies: 53
Views: 6254

Re: 1970s Ampeg SVT refurb

Here's one ... a non-inductive 5 watt 1k 1% ...

http://www.mouser.com/ProductDetail/Vis ... poXn7jg%3d

$3.38 each!!!
by rock_mumbles
Thu Apr 10, 2014 1:41 am
Forum: Garage Talk
Topic: Milkman makes the paper!
Replies: 34
Views: 4264

Re: Milkman makes the paper!

Very cool indeed!
by rock_mumbles
Thu Apr 03, 2014 1:47 am
Forum: Vox/Hiwatt Discussion
Topic: Vox AC15C1 Choke Mod
Replies: 8
Views: 5036

Re: Vox AC15C1 Choke Mod

Yeah I tried to find a schematic to post, but couldn't find anything. I'm 99% sure my mate runs a 10HY @100mA Choke. I'm thinking I will get a 15HY @100mA and try that. If the voltages are still to high then try a 20HY. Thanks for your input, appreciate it :) Look at the DC resistance of the choke ...