Search found 5599 matches

by simon
Tue Apr 20, 2010 9:23 pm
Forum: Valves
Topic: se output transformer question....
Replies: 23
Views: 15886

If you can find them red can RCA 5693s are a nice improvement over the 6SJ7s, but I don't know how obtainable they are now. I saw some on epay last night...worth a punt, maybe? Depending on price, yeah. I didn't play with caps - I have Blackgates, but the three things I did change were the opts, th...
by simon
Mon Apr 19, 2010 11:11 pm
Forum: Valves
Topic: se output transformer question....
Replies: 23
Views: 15886

Just looking at the Sound Practices circuit again www.timebanditaudio.com/300b/WE91A.pdf reminded me that Joe Roberts once told me that the cap on the pentode screen was really important - his advice was use the best PIO I could find. Never did get around to it though...
by simon
Mon Apr 19, 2010 11:03 pm
Forum: Valves
Topic: se output transformer question....
Replies: 23
Views: 15886

If you can find them red can RCA 5693s are a nice improvement over the 6SJ7s, but I don't know how obtainable they are now.
by simon
Mon Apr 19, 2010 10:38 pm
Forum: Valves
Topic: se output transformer question....
Replies: 23
Views: 15886

Hi thomas, which version of the WE91s did you build? Which valves? I built mine maybe 4 years ago with the original Hammond 1627SE opts. I had some AE c cores made for another amp and have been using those since, though I've just put the Hammonds back in in an attempt to rationalise... I don't know ...
by simon
Sun Apr 18, 2010 9:37 pm
Forum: Everyones Projects
Topic: Building an Aikido 'all in one' headphone amp
Replies: 25
Views: 14870

R11 = The manual suggests 1k but theses are missing - will have to order some. As Andrew says, well worth getting a kit of resistors from Rapid, or I can send you a couple. http://www.rapidonline.com/Electronic-Components/Resistors-Potentiometer/Carbon-Film-Resistors/CR25-Carbon-film-resistor-kits/...
by simon
Sat Apr 17, 2010 8:30 pm
Forum: Everyones Projects
Topic: Building an Aikido 'all in one' headphone amp
Replies: 25
Views: 14870

Hi Mark, Right, I've had a think back to when I breadboarded one of these two or three years ago, may be more. Hopefully I've remembered correctly! As Andrew says, the first valve is the amplifier - the 6CG7. R3 and R4 are the cathode resistors. The second valve forms a White cathode follower and pr...
by simon
Tue Apr 06, 2010 9:41 pm
Forum: Speakers
Topic: Vampyrs get some high heels
Replies: 4
Views: 3529

Re: Vampyrs get some high heels

SimonC wrote:Bass has dropped away a little
Is it worth trying filling in the front of the slippers? Might give you a bit more help from the floor?
by simon
Tue Apr 06, 2010 9:38 pm
Forum: Everyones Projects
Topic: 13E1 SE
Replies: 458
Views: 111360

SteveTheShadow wrote:Primary Inductance 15H
What was your rationale for 15H Steve?
SteveTheShadow wrote:Price £ 113.27 each net ex works (Qty 2)
Blimey they quoted me more than that for an anode choke. Sounds alright to me for size.
by simon
Tue Apr 06, 2010 12:40 pm
Forum: Assorted Stuff
Topic: Speccing SE Output Transformers
Replies: 11
Views: 3215

Good question Steve, I often wonder about speccing them myself. If you have MJ he touches on it in "Scrapbox Challenge" SE amp on page 426 (3rd edition). Basically the power rating is the RMS voltage swing squared divided by the tranny "resistance" (2k5, 5k, 10k whatever). A coup...
by simon
Sun Apr 04, 2010 9:46 pm
Forum: Buying and Selling
Topic: for sale, the lot
Replies: 44
Views: 17374

Good stuff :)
by simon
Sun Apr 04, 2010 12:01 am
Forum: Everyones Projects
Topic: another 6s4s single ended amp
Replies: 108
Views: 39757

Aye, and I can remember Ant being in a similar position before on the verge of throwing it all in. Hang in there Ant.
by simon
Sat Apr 03, 2010 11:55 pm
Forum: Buying and Selling
Topic: for sale, the lot
Replies: 44
Views: 17374

Now then Ant, take a deep breath and hang in there. Things may be shite today, they may be shite tomorrow, and they might even be shite next week or even next month too. But you know you're going to regret it one day. The circling vultures might like to think if a little support might be more approp...
by simon
Sun Mar 28, 2010 7:48 pm
Forum: Speakers
Topic: Me new 8" Full Rangers - Tang Band w8-1772
Replies: 322
Views: 132667

Very promising chaps, good stuff. :D

I await developments with interest...
by simon
Sun Mar 28, 2010 7:40 pm
Forum: Everyones Projects
Topic: more on gm70 even more
Replies: 31
Views: 15835

Absolutely. PP isn't my thing but amps like this are inspiring. Very much looking forward to hearing this at Owston one day James. Time for a boatanchor do again?
by simon
Sun Mar 28, 2010 7:37 pm
Forum: Beginners
Topic: Loadlines - voltage swings and driving valves (6EM7 again)
Replies: 22
Views: 7300

Mike H wrote:you get cathode negative feedback as well.
Another beginner's question - what effect does negative feedback have? Is it a problem?