Sonic characteristics of the 807 tube?

analog addict

analog addict

Glory or Death!
As some of you may know, as part of a big haul recently, I picked up what looks to be a PP monoblock based on a set of 807 outputs. One of the tubes is missing, and even though the power supply hasn't found its way into my hands yet, I think it will. I was wondering how the 807 outputs might sound? Is there any reasonable way of converting a setup of this type to a stereo single ended type? Obviously with out a schematic, this is fumbling around in the dark, but....What would be a ball park price for 807 tubes, and what brands are recommended?
Thanks,
Allan

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You're in luck, you can find a ton of interesting 807 tubes at dirt cheap prices, especially comapred to is cousins like EL34 and 6L6. I just PMed you an auction for some very nice looking Amperex 807s that look like they might go for a low ammount on that auction site. That's nuts. If there were a quad of Amperex EL34 or something like that, they bidding would be through the roof! Long story short, you got a great tube to roll, both for sonics and price! (Hmmmm....maybe *I* need an 807 amp?) The top cap is off-putting to some, for safety reasons, so they've fallen out of favor with manufacturers, who need to sell as many products as they can. Just keep curious fingers away, and you'll be good to go! Congrats on the find!
 
If you found another output transformer that matched (good luck, those are rare), you could easily build another. At that point you'd either need two power supplies, or a single larger one. Tube circuits aren't as complicated as others, so it'd be totally possible for you to trace out the current scematic and make another, or use the existing chassis/sockets/transformers to build a similar circuit more to your liking.
 
hey-Hey!!!,
The 807 is a fine tube. As with the 'favourite tube thread' it is dependant on the support circuitry and parts selection. The LS63 should be a *FINE* output. I have assisted in creation of an 807 amp running a 10k a-a output and 40% taps for the g2. I liked it a lot, one of my favourites so far.

If you want to ebay that single LS, there are a few good outputs that you can get a pair of for the same money. Those LS cases grab a premium, that's for sure...:)
cheers,
Douglas
 
I was going to be doing a SE 807 amp, but recently snagged 4 1625's with sockets, and some sweet WW2 Army PP UTC 6L6 OPTs so I traded the 807's away.

as for brand, ya can't go wrong with RCA :thmbsp:
 
I'm now planning...

...on picking up the power supply this weekend, so I'll post a pix of what it looks like when I finally lay my hands on it. I like the idea of duplicating the circuit to essentially build a parallel monoblock. Figuring out what to do output transformer-wise will be the difficult part I think. maybe look for a pair of something on E-pray...:scratch2:


While I'm waiting, here's the view up the skirt....:D Lost the E-Pray auction on those tubes while doing a soccer function...:tears:
 

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markus said:
I was going to be doing a SE 807 amp, but recently snagged 4 1625's with sockets, and some sweet WW2 Army PP UTC 6L6 OPTs so I traded the 807's away.

as for brand, ya can't go wrong with RCA :thmbsp:
Click to expand...

Not to thread hijack, but I have some 1625 tubes that I want to do a project with, as well! Can't wait to see what you do with yours!

I love RCA. Good tubes, and often overlooked by the audiophool crowd.
 
analog addict said:
...on picking up the power supply this weekend, so I'll post a pix of what it looks like when I finally lay my hands on it. I like the idea of duplicating the circuit to essentially build a parallel monoblock. Figuring out what to do output transformer-wise will be the difficult part I think. maybe look for a pair of something on E-pray...:scratch2:


While I'm waiting, here's the view up the skirt....:D Lost the E-Pray auction on those tubes while doing a soccer function...:tears:
Click to expand...

Dude, that's some seriously nice looking iron. I can't help but wonder what the power supply looks like. If it's anything like the amp, it should be impressive! Careful with that amp, tho, those caps look really old! Also don't worry about the tubes, there are PLENTY of more that will come along, I'm sure. Like another poster said, RCA and other brands are awesome, too!
 
Squidward said:
Not to thread hijack, but I have some 1625 tubes that I want to do a project with, as well! Can't wait to see what you do with yours!

I love RCA. Good tubes, and often overlooked by the audiophool crowd.
Click to expand...


Me too....................on both counts.:yes:
 
Finding a mate for that output transformer is likely to be very difficult. Pac mentioned an UTC LS63 output iron. Is that correct? The UTC LS-63s are one of the less common UTC transformers. I only know this because I spent nearly ten years looking for a mate for my single, before I finally succeeded in locating another one. Had it not been for AK, I would probably still be looking too (or begging to buy yours). Other UTC transformers pop-up regularly on that action site, but not this model. :no:
 
analog addict said:
I was wondering how the 807 outputs might sound? Is there any reasonable way of converting a setup of this type to a stereo single ended type? Obviously with out a schematic, this is fumbling around in the dark, but....What would be a ball park price for 807 tubes, and what brands are recommended?
Thanks,
Allan
Click to expand...

to answer two of your original questions:

I'd go RCA all the way - if I'm not mistaken, they designed the 807, and many of the other tube manufacturers got close, but not *dead-on* as far as build quality / sonics . . . if I can find them I believe have a small stash of 807s . . since I'm going with 1625's, shoot me a PM :thmbsp: also, even on the Bay they're not expensive, maybe $10 - 15 a pop . .. even cheaper at radio swap meets (even NOS).

any chance you can trace the circuit ? (TDSL and someone with the spec's on that UTC transformer would be essential).

(I reaaaaalllly need to start my own thread, but) with my 1625's, I plan on going Class A PP with my Army 9K OPTs. I have some disgustingly HUGE PT's too :D I figure I'll just go by the tube data:

http://tdsl.duncanamps.com/show.php?des=807

(notice I linked to 807 data, since they are the same.)

by the way - just did some quick hunting - looks like the LS-63 was designed for PP Triode & has 7 - 50K Hz frequency response !:jawdrop:
 
Oof!...This had got to be the biggest transformer I've ever seen!

And it weighs a ton...here are the pix. The seller said his Dad worked on this setup in the late 40's when he was a young man, so all the components have got to be close to 60 years old...:yikes:

This is going to be a long term project, that's for sure. With some time and a bunch more experience and help, I think I could wind up building something really special. He sold me another transformer which I will post in a separate thread. Maybe I can eventually get two matched output transformers for the new one and the LS-63 combined:scratch2: ....Comments???

Also, can I assume the unmarked tubes are rectifiers of some type, say 5U4's?
 

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I don't have a pair in front of me, and I can't be sure from the angle of the picture, but those are *probably* either 5U4's, or 5R4's . . .

as for getting a matched set of OPT's, I know there's a company (someone I'm sure will chime in with the name) that can duplicate classic (and new for that matter) OPT's with new construction. Maybe Heybor ? can't remember off hand . . .

EDIT: yes - its Heyboer :thmbsp: http://www.heyboertransformers.com/

you could get that LS- series OPT cloned X2, and then sell the single LS OPT to recoup some or all of the cost . . .

that will really sweet once you can clone the single amp/power supply and have a stereo pair :yes:
 
analog addict said:
And it weighs a ton...here are the pix. The seller said his Dad worked on this setup in the late 40's when he was a young man, so all the components have got to be close to 60 years old...:yikes:

This is going to be a long term project, that's for sure. With some time and a bunch more experience and help, I think I could wind up building something really special. He sold me another transformer which I will post in a separate thread. Maybe I can eventually get two matched output transformers for the new one and the LS-63 combined:scratch2: ....Comments???

Also, can I assume the unmarked tubes are rectifiers of some type, say 5U4's?
Click to expand...
Pac may have given the best advise to sell your LS-63, and to buy a couple of brand new OPTs instead. Finding a match for that particular unit is going to be extremely diffcult.
 
my guess is that stromberg amp had 6L6 or 6L6G output tubes, so it's in the ballpark for sure. If your amp used higher plate voltage to take advantage of the 807s, this one one *could* be coming up short though . . .
 
Yes Doug certainly did a number on my 807 amp (second generation)! Less than a week after AK Fest we modded my 807 amp with some of Doug's magic. Next to his 4E27 amp, which is an astounding creation, I have never heard any better amps. But as for the tube the 807s were very nice, I just happened to roll in some 5933s (Sylvania) and they were considerably nicer. More life, more air, great detail. Now I only had one set of RCA 807s to compare to, but in this case it was a significant difference. So the bottem line is 807s are nice and a good deal right now, 5933s are a good deal and may bring more to the table so keep your eyes open.

Terry
 
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