tube phono amp req'd

[Raj1]

Hi,


Do you know of a place in europe which sells 260v-0 trannies at a reasonable price? I have searched the web on UK suppliers and they don't seem to have anything of that value off the shelf, whcih means they'll have to be custon wound, and for that the UK dudes aren't cheap.


Thanks
Raja

 

[Raj1]

Hi Frank,

also just to confirm I'm getting the right types that should be readily available in europe,

7025's should be tesla brand?

12bh7a's what brand?

what about the power reg tubes, any preffered brands here for 5651 or the el86's?


thanks
Raja

 

[fdegrove]

Hi,

Do you know of a place in europe which sells 260v-0 trannies at a reasonable price?

Not really...Mine came from RS but that's many years ago, I don't think they still carry those.
Did you check with Maplin?

Either way, anything from 250 to 270VAC should be fine, a 6.3VAC winding (check current) for the EL86 and 12AX7A can be included on the same xfmr.

7025's should be tesla brand?

Fine by me. E83CC Tesla is very good sounding too.

12bh7a's what brand?

RCA is my prefered US brand.

what about the power reg tubes, any preffered brands here for 5651 or the el86's?

5651 can be RCA, otherwise the UK CV449 (OG3) should be allright too.

EL86, I like the Siemens but Philips/Mullard should be fine as well.
Just don't buy any former east-block ones such as Telam etc.

Cheers,

 

[klitgt]

I have a specimen of the L'audiophile Le Tube preamp that has been stripped down to work only as a riaa (for MC).

It is a 2 channel (stereo) construction with 2 (TWO!) tubes total = 1 tube per channel.
According to a review in a French magazine it is among the most neutrally sounding tube amps available.

Interested? Give a bid. It cost Euro 785 when it was brand new in 1983.

 

[fdegrove]

Hi,

I have a specimen of the L'audiophile Le Tube preamp that has been stripped down to work only as a riaa (for MC).

Unless some stepup xformers are used on the input that's MM only, not MC.

I think the original "Le Tube" used just a single triode (1/2 12AX7A) per channel.

You could put it on sale in the "Trading Post" part of the "Market Place" section of the forum.

Cheers,

 

[jsn]

other options

Other tubed phono stages out there:

The Bottlehead Groove Thang (precursor to the Seduction kit, but using different tubes). There are quite a few variations on this by lots of folks, including Gary Pimm.

http://www.valvediy.com/groove.html

Jeremy Epstin's direct 6c45 and 6gk5 phono stages. Direct coupled or not.

http://home.earthlink.net/~jeremyepstein/6c45riaa.html

I think I am going to give his 6gk5 version a shot as soon as I finish a few other projects.

jsn

 

[JojoD818]

Frank,

Why just now?

I just finished the line stage with phono preamp that I built using the phono circuit you gave with the additional time constant resistor on another thread here. It sounds very good btw. Thanks for the help Frank!

Maybe I can try the circuit you posted earlier here? Is the pot labeled 100k the only revision in that circuit? I have a 250K Noble pot which I can use right?

Thanks!
JojoD

 

[fdegrove]

Hi,

Is the pot labeled 100k the only revision in that circuit? I have a 250K Noble pot which I can use right?

Glad to see you like the preamp so much.
IIRC you built the phono section Planet10 posted with the added Neumann constant and my buffer stage ?

The 100K pot, or 250K, can be used instead of the 1M pot that you need to use when the buffer is preceded by the phono stage I posted before.
That's the one using the active RIAA correction and the 1M pot resistance is mandatory to maintain RIAA accuracy.

The buffer on its own can easily take a lower value potmeter.

Cheers,

 

[JojoD818]

Hi,



Glad to see you like the preamp so much.
IIRC you built the phono section Planet10 posted with the added Neumann constant and my buffer stage ?

The 100K pot, or 250K, can be used instead of the 1M pot that you need to use when the buffer is preceded by the phono stage I posted before.
That's the one using the active RIAA correction and the 1M pot resistance is mandatory to maintain RIAA accuracy.

The buffer on its own can easily take a lower value potmeter.

Cheers,

Frank,

The line stage is a CC+CF circuit and the phono is indeed what Planet10 posted with the added resistor you indicated.

Now that is a very simple solution , putting the pot after the buffer. Thanks!

JojoD