Need help with 50 Watt build!!!!!

Post by **Scumback Speakers** » Sun Dec 02, 2007 8:09 pm

mwm523: My goal for this amp would be to basically setup a fatter tone out of Ch II, then have Ch I be the lead solo tone from my A/B footswitch on my pedalboard.

So, realizing that 2-3 is the actual unattenuated volume I can get away with, I'll have to put in the PPIMV mod to run the amp around noon on the MV so I can retain some decent cleans but start to have more gain for my solos.

Without the cap at all, where do you wind up running the amp on your PPIMV? 1/4th up, 1/3rd, 1/2 (can't imagine you going past 1/2 with the volume these things put out), or what?

jct: If Ch I stays brighter, then perhaps what I need to do is, ahem...experiment with the cap...pretty sure I have a 100pf George put in as well as a .047 pf. Hell, maybe I'll break out one of my prized .022 600 volt Bumble Bee caps and put it in there.

I know...Gibson cap from the 50's in a 50w Plexi? (For shame, Jim, for shame! LOL)

jctaudiodesigns · Post by **jctaudiodesigns** » Sun Dec 02, 2007 9:15 pm

Southbay Ampworks wrote:
jct: If Ch I stays brighter, then perhaps what I need to do is, ahem...experiment with the cap...pretty sure I have a 100pf George put in as well as a .047 pf. Hell, maybe I'll break out one of my prized .022 600 volt Bumble Bee caps and put it in there.

Of course, the other thing you could do is change the coupling cap from V1 to the next stage. (take a look at the layout for the 70 and up lead specs) The nice thing about changing that cap is that unlike using the bright cap, the frequency response should stay the same though at all volumes.

toner · Post by **toner** » Sun Dec 02, 2007 9:32 pm

Southbay Ampworks wrote:...Hell, maybe I'll break out one of my prized .022 600 volt Bumble Bee caps and put it in there...

.022uF ???

.022uF = 22,000pF You might as well just hardwire bypass the volume pot at that point.

Jim,
Just experiment with different bright and mixer caps. The bright cap's effects depend on the volume pot setting and the mixer cap doesn't (as much). You can even lower the mixer cap to 250pF and keep a larger bright cap like 500pF with good results.

Roe · Post by **Roe** » Mon Dec 03, 2007 5:05 am

bartak wrote:... playing in a room by myself I like the lower value or no cap but with the band the higher value cap helps cut through the mix and open the amp up. One of the best things I've learned from playing shows is find the tone that sounds good to your ears then add a little treble and mids, It may sound a little harsh in front of it but it will translate to the audience much better. also the ear plugs that you all should be wearing in front of one of these amps turned up, helps cut some of the highs.

that's pretty much my experience as well although I haven't got my 50w kit yet

neikeel · Post by **neikeel** » Tue Dec 04, 2007 5:04 am

mwm523 wrote:
jctaudiodesigns wrote:Wow, ok now I have an amp! I ordered a TSL 100 that was modded by Voodoo amps a couple of months ago, I spent a lot of money on that amp, now I am kicking myself. I will NEVER buy a major manufactures amp again. I am now wondering If I can design my own high gain amp. Maybe add a extra gain stage. My mind is going at 100 miles an hour. One thing is for sure, the TSL is going on ebay.

What should I build next?
Yep, you're hooked...

Yup

I have found the cab and speakers really affect th echoice of bright cap. If you are using bright speakers (Hs usually) and low volumes you hardly need a cap at all. I think that if you are using single coils a 0.022uF rather than 0.0022uF ch1 coupler is better.

Other option is a 390pF mixer bypass cap (or like Udos JTM45 no cap at all).

I run my 50 watter around 6 on the volume (give or take a notch) so I still need a bit of bright cap (820pF-500pF).

Experiment!