• TGP is giving away a Strat, Tele, and Jazzmaster. Click Here for full details.
    Click Here to upgrade your account and enter today!

Just acquired an amp with NOS tubes- need some advice

skhan007

Silver Supporting Member
Messages
9,380
I just received this 2006 Alessandro Black 'n Tan amp. It's been on my list for over a year and I'm happy to have found a great deal on one. This is one of the "high end" ones with special filtercaps, special wiring, etc., etc. Sure looks pretty inside & out, though!

It came with these tubes (see pics): Dynaco labeled EL34's, which the original owner tells me are Telefunkens. In the preamp section we have two of these JAN Philips labeled 5691's.

Can anybody help me understand what to look for as far as date codes, place of manufacture, and who made them? The Dynaco's obviously say "Made in Germany", but how would I know they are Telefunkens? The original owner told me this amp had RCA's in the preamp section, but how do I know they are RCA's when they're labeled JAN Philips? Just looking to decipher some codes.

These tubes sound fantastic, by the way. They have way more clean headroom than I need, so I really have to get the amp's volume around 1-2 O'Clock to get my gain on.


 

rockon1

Platinum Supporting Member
Messages
12,800
The EL34's look like these RFT's that just coincidentally happen to be Telefunfen labeled .

http://www.tubemongerlib.com/gallery2/v/EL34/RFT+EL34+Telefunken+Label+-+East+Germany.jpg.html

The 5691's look like the RCA's but I suspect they are indeed what they say they are JAN Phillips.

Heres a link to a picture of an RCA
http://www.tubemongerlib.com/gallery2/v/EL34/RFT+EL34+Telefunken+Label+-+East+Germany.jpg.html

Heres a link to a picture of a JAN Philips
http://www.cryoset.com/catalog/product_info.php?products_id=270&osCsid=96kba50l4bhjihonlgpuhbaet1

Im sure somebody with more expertise with these tubes will be along shortly ....Bob
 

mc5nrg

Silver Supporting Member
Messages
9,914
Unless the guy who sold you the amp retubed it with never used tubes before sending it to you the tubes are USED old stock. Quality tubes and a great amp but UOS.

Probably by the time the JAN Philips tubes were made RCA had left the tube manufacturing behind. Can't explain the seller's reference...maybe they still distributed. I would think chances are regardless of the tubes actually inserted in the sockets you'd have to crank a non-master volume amp with 2 EL34 power tubes some to get a distorted tone, influenced also by the guitar pickup factor.
 

skhan007

Silver Supporting Member
Messages
9,380
Yes good point- Used old stock. When he got the amp, the tubes may have been new old stock. As for the 5691 tubes, they are labeled made in USA on the top and per Bob's info/links above, they do indeed date to 1985. Not exactly what I think of when I think "vintage". But whatever. These are the tubes that came with the amp. They look identical to the RCA's except they don't have a red base nor the RCA logo. If they're stamped "made in USA" they are obviously not European tubes, like other Philips tubes I've seen. The seller advertised (on TGP) that the preamp tubes were RCA 6SL7's.

As for the EL34's, they look spot on to the RFT/Telefunken pics provided by Bob. There's not any date coding or anything else that I can see on these tubes, however.

And yes, this amp must be up past Noon to get good gain going.
 

skhan007

Silver Supporting Member
Messages
9,380
OK- got some more info.

The Dynaco labeled EL34's are not Telefunken's. They are early 70's RFT's. Fine tubes, but not Telefunken's.

The Philips 5691's are (surprise) not RCA's. They are mid 1980's Philips (typically made by Sylvania) industrial version of the 6SL7.

They were advertised as Telefunken's and RCA's-- but I just confirmed with George Alessandro that the tubes I got in the amp are typically what he uses. I suppose all is good.
 
Last edited:

rockon1

Platinum Supporting Member
Messages
12,800
The EL34's look like these RFT's that just coincidentally happen to be Telefunfen labeled .

http://www.tubemongerlib.com/gallery2/v/EL34/RFT+EL34+Telefunken+Label+-+East+Germany.jpg.html

The 5691's look like the RCA's but I suspect they are indeed what they say they are JAN Phillips.
OK- got some more info.

The Dynaco labeled EL34's are not Telefunken's. They are early 70's RFT's. Fine tubes, but not Telefunken's.

The Philips 5691's are (surprise) not RCA's. They are mid 1980's Philips (typically made by Sylvania) industrial version of the 6SL7.

Not sure how I should react to this as they were advertised as Telefunken's and RCA's.

....
 

skhan007

Silver Supporting Member
Messages
9,380
You hit the nail on the head, Bob. Right as usual!

I corresponded with George Alessandro and he confirms these tubes are what he uses.
 

rockon1

Platinum Supporting Member
Messages
12,800
You hit the nail on the head, Bob. Right as usual!

I corresponded with George Alessandro and he confirms these tubes are what he uses.
I feel a need to be heard or acknowledged but am trying to change my ways. lol!
Tubemogers pic library is a great source of info.:BEER Bob
 

skhan007

Silver Supporting Member
Messages
9,380
I feel a need to be heard or acknowledged but am trying to change my ways. lol!
Tubemogers pic library is a great source of info.:BEER Bob
Intermittent positive reinforcement is the best way to reward, encourage, & sustain good deeds! You 'd man as always!

I'm told that there's very little variation to be had in swapping around octal based preamp tubes like 6SL7's/5691's. They are a specific breed with little difference between redbase RCA's, Philips/Sylvania 5691's, or others. I'm told that the ones I have are a bit more on the "edgy" side.

As for the poweramp tubes, these RFT tubes (George Alessandro emailed me telling me their actually Siemens) are pretty good. Honestly though, I threw some Valve Art KT66's in there and they are fantastic!! Gotta try some EL37's at some point as well.
 

Swarty

Member
Messages
1,130
The only issue I see is that if you purchased the amp on the basis of Telefunken EL34s there is is a huge price difference. Telefunken EL34s typically go for several times the price of RFTs (aka Siemens/Dynaco/National, etc...).
 

skhan007

Silver Supporting Member
Messages
9,380
The only issue I see is that if you purchased the amp on the basis of Telefunken EL34s there is is a huge price difference. Telefunken EL34s typically go for several times the price of RFTs (aka Siemens/Dynaco/National, etc...).
Yes, this is true. Not sure what I can really do about it, though. The seller was a pretty nice guy and took a pretty big hit selling this amp for much less than the cost of a new one. He did state/advertise NOS Telfunkens, however.
 




Trending Topics

Top