I’ll try to answer a few of the points made in one single post, hope it doesn’t make things too confusing.
BobW wrote: Ayan, fwiw, the signal level into the amp was typical of my guitar (strat), not humbuckers. I also don't use stomp pedals or any thing else to boost the gain out of the comfort zone, as you suggsted. My scope observations were a fair measurement to the OD gain settings I chose and prefer, and obviously didn't crank everything to 10 as most don't.
I think we’re saying the same thing, basically. You said everything looked fine, and as it turns out you tried the amp under reasonable conditions. I had said that if you cranked everything up, you would see how the 100uF VS 22uF cap choice will have an effect of the amount of ripple present riding on the signal at the speaker output. So I think both of our statements are inclusive of each other.
As for the volume the amps are played at, I agree, and I never set everything on 10 myself. However, I know some people that do; while I am not sure I understand why that is a necessity to them, it is, so there are cases where the consideration to use a beefier power supply has to be made.
jelle wrote:Hi Gil,
Guess I just misread it...sorry.
It would be nice if you could make some material available, but friendships are worth a lot! Certainly more than an amp to me.
I read that you sold a few amps and that you are planning to build another one.
What kind of amp are you planning to build next?
Jelle, it seems that you know more about me than I.
When I am supposed to build another amp? I'd like to know so that I can schedule the rest of my life accordingly.
I think one likely scenario is that I buy a Vox AC30CC amp next.
jazzyjoepass wrote:Sorry, just want to try to steer topic towards the totem pole thing.
Anybody measured the voltage drop across each capacitor in a totem config?
Seems that the voltages are not equal even with the resistors across the caps. The top cap always gets the larger charge than the bottom one.
Anyone can confirm for me? Mines around 360V on the top cap and 100V on the bottom cap.
Interesting eh?
Jazzyjoepass, are you talking about the voltage drop across each cap (so the top cap voltage is
not refrenced to ground)? If so, there is definitely something not right with your power supply. Have you measured your resistors? Either they are not the same, or one of your caps has goone seriously bad on you. The totem-pole voltage will not be identical, as the resistors used are usually 5% tolerance, and then there is the ESR of the cap in parallel with each resistor, so they may be say within 10%. But if you're getting such a tremendous difference in voltage drop, it means something is way off, and I would recommend you have a close look ASAP.
groovtubin wrote:Gil, w/what little i know @ power supplys, i do know this, LOOSENING up the PREAMP w/10uf`s has to play a part in the "give up the goods" Mike Soldano does the same thing in a SLO. HUGE filtered power supply, and a rather small filtered preamp section, loose greasy gain, yet punchy and huge bottom end, lovely! Your thoughts? jim
Jim, I think what Soldano does allows him to have a ripple-free B+ voltage, since he has ample filtering up front, so there will be no sag in that amp. The fact that he uses 10uF downstream is only half of the picture, since the dropping resistor that preceeds a cap to ground will -- along with the cap -- set the break point of the low pass filter the two of them form. So, for example and only theoretically, a 10uF cap to ground following a 22K dropping resistor would give the same filtering as a 22uF cap to ground following a 10K resistor. However, using a larger series resistor will drop the B+ voltage more, which will yield a lower plate voltage on the tube giving a browner sound. I'm not familair with the Soldano sound too much, and I don't know what amp you're referring to. I like the SLOs I use to hear as played by Clapton, Gary Moore, etc. They sounded good, punchy and on the bright side -- I like bright, for what it's worth.
Cheers,
Gil
