Boy, is this a dull forum... [message #11351] |
Tue, 14 November 2006 17:32 |
SteveBrown
Messages: 330 Registered: May 2009
|
Grand Master |
|
|
Okay, now that I caught some attention I'll say, well, it is kind of dull. Where are the posts? What are you all working on? What's on the bench? Ideas? I wish I'd built.. ? what's up? But also, I have a question. On another forum I read a review of caps. I have long believed that no caps are good caps, but lets face it, sometimes they're needed. So how many, if any, folks have tried V-Caps? They were second rated in that review only to AN Silver caps. I ordered a (very expensive) pair, but have not received them yet. I'll let you know what I think, but in the mean time, anyone else with some experience?
|
|
|
|
|
|
Re: Boy, is this a dull forum... [message #11355 is a reply to message #11354] |
Thu, 16 November 2006 07:27 |
SteveBrown
Messages: 330 Registered: May 2009
|
Grand Master |
|
|
Sounds interesting. And as you likely know, the 2A3 is a 15w tube, and the 300b is a 40w tube, so it isn't just heaters that need to change. If you slap a 300B in the 2A3 circuit, without altering the operating point for the 300b, you'll hear a difference (due to the diff tube), but you'll not really get any more power out. Also, the 300b, borrowing the 2A3's bias R may or may not be at a good operating point, you'd have to look at the plate curves to figure that out. I suspect it will run just fine, but may not be the best representation of what a 300B can do. Overall, sounds like you'll have fun. Keep us informed on the progress!
|
|
|
|
Another Way [message #11357 is a reply to message #11351] |
Fri, 17 November 2006 12:31 |
Skip
Messages: 27 Registered: May 2009
|
Chancellor |
|
|
About six weeks ago I put Magnequest EXO-45 transformers and BCP-15 extralinear chokes (all M6 cores) in my standard Bottlehead Sex Amp. I also replaced the .1 ufd. interstage coupling cap with V-caps. I think I've got enough hours on it now, and it sounds wonderful on my Lowther Medallion IIs (15 ohm PM2Cs). Richer mids and some real bass, though it naturally doesn't go deep. My combination of mods made the cap change largely unobservable, of course, but the total result is sure there.I'm not about to spend the bucks it would take to replace the parafeed cap (1 ufd.) with a V-cap. I'll try and Auricap or a motor run (if I can find a 1 ufd. motor run) there in a few months. Skip
|
|
|
|
|
Subject should be: About the V-Caps [message #11360 is a reply to message #11359] |
Fri, 17 November 2006 15:02 |
Skip
Messages: 27 Registered: May 2009
|
Chancellor |
|
|
I'm fairly sure the amp has good bass, it does through phones. The Lowther Medallions run out around 60-70 hz or so with hints below that. Might need a transconductance amp to push those drivers much lower. I'll work on something with more watts as well. 2 watts with a baffle step correction (line level before the amp) pushing up the lows has its limits.Skip
|
|
|