Croft 25R Preamp Tube rolling

[Jimbo]

That's a good list of contenders mate. I shan't be participating because the Telefunkens are doing the business for me.

That croft set up is a beauty. I'm half tempted to see if the phonostage in the pre is available as a separate unit

O

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The phono stage in the pre is available separately as the RIAA or RIAA R or RIAA RS (two box with separate p/s).
All the separate phono stages are better than mine in the 25R preamp! They have a more sophisticated set up with three valves. Glenn said there was more space in the separate phono stage to do a better job!

Personally I would go for the RIAA R regulated phono stage. All valve of course, so plenty to play around with. Think there are 5 valves in this phono.

[Bigman80]

The phono stage in the pre is available separately as the RIAA or RIAA R or RIAA RS (two box with separate p/s).
All the separate phono stages are better than mine in the 25R preamp! They have a more sophisticated set up with three valves. Glenn said there was more space in the separate phono stage to do a better job!

Personally I would go for the RIAA R regulated phono stage. All valve of course, so plenty to play around with. Think there are 5 valves in this phono.

As with everything, it'll come down to price but thanks for the info Jim, it's food for thought!

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[Jimbo]

As with everything, it'll come down to price but thanks for the info Jim, it's food for thought!

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Plenty of tube rolling opportunities in the RIAA R!

[Bigman80]

Plenty of tube rolling opportunities in the RIAA R!

Just had look............I'll wait for a second hand one 🤣

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[Frazeur1]

I agree with that, the stock JJ's are indeed pretty darn good. Good enough to keep me from continually messing around, especially at the price. More music, less faffing around....

[Jimbo]

So I decided to try rolling the tubes in the Croft 25R back to the original JJTesla ECC83S tubes it came with. I have had great results in the regulation stage so I thought lets try the phono stage.

The JJ Teslas did not even last the night! Popped the NOS Tesla ECC83 37,s back in. MASSIVE difference. No comparison at all. They slaughter the JJ Teslas on every account! Won't be doing that again. :roll eyes:

Whilst I had the lid off decided to use some tube damping rings. 2 on the line stage tube and 1 each on the phono stage tubes. I have read I would loose some dynamics and detail but this is not what I have found. The tube rings have given the sound more precision and image stability.

More listening required.

[Bigman80]

So I decided to try rolling the tubes in the Croft 25R back to the original JJTesla ECC83S tubes it came with. I have had great results in the regulation stage so I thought lets try the phono stage.

The JJ Teslas did not even last the night! Popped the NOS Tesla ECC83 37,s back in. MASSIVE difference. No comparison at all. They slaughter the JJ Teslas on every account! Won't be doing that again. :roll eyes:

Whilst I had the lid off decided to use some tube damping rings. 2 on the line stage tube and 1 each on the phono stage tubes. I have read I would loose some dynamics and detail but this is not what I have found. The tube rings have given the sound more precision and image stability.

More listening required.

Yup, Valve rings do bring the precision. I love them. JJ valves aren't at the level of the original Tesla's or Telefunken.

[User211]

Maybe try the ECC803S 32 at some stage. It is as good as the Telefunken ECC803S. You may read differently elsewhere but I struggled to tell the two apart after days of trying. Weeks actually now I think about it.

[Jimbo]

Maybe try the ECC803S 32 at some stage. It is as good as the Telefunken ECC803S. You may read differently elsewhere but I struggled to tell the two apart after days of trying. Weeks actually now I think about it.

I will try and get hold of some. You haven't got any knocking about have you Justin.

[User211]

I will try and get hold of some. You haven't got any knocking about have you Justin.

No I sold them with the amp. It doesn't look like the 37 (Trinec) factory ever made an ECC803S, it being the sole preserve of the Rosnov (32) one? Could be wrong, though.

Have a look at the picture below. A few (but not all - just the ones I sold with the amp) 12BH7As are in there.

The 4 RCAs at the top left are the Mexican mid 70s grey short plates. The two in the leftmost middle row are RCA grey long plates, as are the two on the bottom row two in from the left (but white print from an earlier period). The Daddy's, though, are the two by the white boxes, packed March 1966, with long black plates. Cream of the crop, I think.