| Joel |
Does anyone know where online I can find a schematic of the Western Electric "model 91" amp? I can't seem to locate one.
I hear it described as a classic. The single pentode voltage amp/driver stage is interesting. Any thoughts on a #32 pentode driving a #45? I have two laying around.
I can't decide whether to do that, or just use a 6F8-G direct-coupled.:scratch2:
Joel |
|
|
| fdegrove |
Hi,
I've got the circuit diagram of the WE91B and also a french adapation in some books.
Everything is in French though.
The B uses an input xformer,a 310A penthode (you won't need this stage) followed by another 310A driving a WE300B loaded by a WE171A OPT.
Joel,if you need a scan of it I can have it done at the shop close by.
Cheers,;) |
|
|
| Joel |
Thanks guys.
Robert - that was an interesting page. Thanks.
Boy, they sure weren't afraid of stringing a whole bunch of stages together. They aren't "minimalist", that's for sure.
Lots of iron in there too.:up: |
|
|
| fdegrove |
Hi Joel,
If you need further developments on these amps I intend to reread the articles on the mods by Jean Hiraga on the Zaila and WE amps.
Let me know if you're interested.
Ciao,;) |
|
|
| Noam |
Definitely interested, Frank. I haven't seen those articles.
A group of nine of us are preparing to build amps based on the revised WE91 (SP#1 or Angela circuit), so any and all info is helpful.
cheers,
Noam |
|
|
| fdegrove |
Hi,
I'll have the articles scanned tomorrow and e-mail them to you.
Let me tell you up front these are one of the best 300B based amps I've ever heard.
See you,;) |
|
|
| Noam |
Thanks a lot Frank, it'll be much appreciated. And for the comment too; I've never heard one of these amps, it's a blind-faith, they-twisted-my-arm thing. Jack E is already winding our transformers.
Noam |
|
|
| Brett |
| quote: | Originally posted by fdegrove
I'll have the articles scanned tomorrow and e-mail them to you.
Let me tell you up front these are one of the best 300B based amps I've ever heard. |
Could I be included too please?
There were also a couple of extended articles in Glass Audio from about two years ago on the WE91A
Cheers |
|
|
| fdegrove |
Hi Brett,
Long Time no see.
Sure,in fact I may have the GA articles as well and if you could post the scans here for me that I'll mail you I'd be grateful.
See,I still can't seem to post any local files from the PC to the forum.(firewall probably)
Cheers,;) |
|
|
| Brett |
| quote: | Originally posted by fdegrove
Hi Brett,
Long Time no see. |
Hi Frank,
Yeah, been busy with work, and a dose of the killer flu that's raging through here presently.
| quote: | Sure,in fact I may have the GA articles as well and if you could post the scans here for me that I'll mail you I'd be grateful.
See,I still can't seem to post any local files from the PC to the forum.(firewall probably)
Cheers,;) |
Glad to post any pix that you'd like me to on your behalf.
I finally found the drivers for my scanner, and if I can get a parallel cable for it, I'll be working again, and I'll do the articles I have if they're different.
TTFN |
|
|
| Joel |
Thanks Frank, I'd be interested in any extra info you have as well.
And also if anyone has any experience with the DHT pentodes, 24-A, 32, etc. please chime in. |
|
|
| fdegrove |
Hi,
The stuff I prepared for you all is ready to be scanned but unfortunately I won't have time tomorrow nor this weekend to work on this.
So please be patient,I hope to send it to you all by the end of next week.
If anyone else is interested please let me know and state a valid e-mail addres if you disables private mail for the forum.
Thanks,;)
| quote: | | The single pentode voltage amp/driver stage is interesting. Any thoughts on a #32 pentode driving a #45? I have two laying around. |
The penthode + triode combo is generally a good sounding recipe.
I often noticed the penthode adding a bit more life and sparkle to the DHTs.
Ciao,:cool: |
|
|
| Ciscokid |
Hi,
Could I be included on this we91 info?
Best regards,
ck |
|
|
| jeff mai |
| quote: | Originally posted by Joel
Does anyone know where online I can find a schematic of the Western Electric "model 91" amp? I can't seem to locate one.
I hear it described as a classic. The single pentode voltage amp/driver stage is interesting. Any thoughts on a #32 pentode driving a #45? I have two laying around.
I can't decide whether to do that, or just use a 6F8-G direct-coupled.:scratch2:
Joel |
I've built the WE91 circuit using several different input pentodes. I liked the 6SG7 best (keep it biased away from it's remote cutoff region.) The 6J7 and 6SJ7 were pretty good too. I preferred all of these to using the C3m, which is pretty highly regarded. The 6C6 (which I haven't tried) was the original valve used in the 91 circuit and they are plentiful compared to the WE types. The 6SH7 looks interesting, too, but I haven't tried it yet.
A very nice improvement in sonics for all of these pentodes is to use an 0C3 VR tube to supply the screen. Give them a try.
Sacrificing maximum power, I'm really enjoying a simple paralleled 6N7 triode as a single stage driver for the 300B. It works really well for a 45, too. |
|
|
| Noam |
Attached is the revised 12/93 schematic from SP #1 where Joe Roberts spoke very highly of this circuit. He got rid of the first 310 stage and feedback loop, and added a choke in the power supply.
Another popular revision is the "Angela 91", you can find the info here. http://www.angela.com/catalog/how-to/model.91.html
Apart from these I haven't found that much info (considering how many people have apparently built these). Look forward to the info/articles from Frank.
Noam |
|
|
| Joel |
| Thanks for posting that Noam.:) |
|
|
| Noam |
Hi Frank,
just a reminder.. if you have a chance to send those articles along to one of us, we can post them.
tia
Noam |
|
|
| fdegrove |
Hi,
Sorry to keep you all waiting.
I haven't scanned the articles yet but found a site that as them online (minus the articles).
AQUABLUE
Keep in mind that the 310A is quite likely unobtainable today.
Cheers,;) |
|
|
| fdegrove |
Hi,
Here's another one that sounds great:
ZAIKA
There are again a lot more 300B combos on the same site.
Cheers,;) |
|
|
|
