Croft 25R/7 tube rolling

[IHP]

Two questions !

I wondered if someone would be able to confirm whether my recollection is correct on valve layout on the 25R pre please ?

1. There are 5 x ECC83, I'm thinking the first two from the left are for the phono stage, the 3rd line stage and the 4th and 5th for the power supply.

2. In terms of tube rolling, I'm thinking the main benefit can be achieved by experimenting with the line stage in the pre ?

3. Is there much benefit to be had in rolling the valve in the 7 Power ?

I have in the past rolled and found it to be frustrating. However I've had this combination of amps for some time now and fancy having another go but taking things slowly, evaluating over a long period and trying only one change at a time.

Any knowledge/views gratefully received.

Thank you :-)

[worrasf]

Yes - and no[emoji1]
The 2 at the left are phono stage and are ecc83's /12AX7 the 2 to the right are power stage and are ecc83's/12AX7
The middle is the line stage and not ecc83.
Glenn puts a JJ ecc99 here but will also take a 12BH7 - personally, I am using a Simens E82cc here.
After more tube rolling than I care to remember I have settled on Siemens or Siemens & Halske for all 25R tubes - I have found that the 7 monoblocks work very well with gold pin JJ ecc99's.

[Canetoad]

Mine has 5 ECC83s :scratch:

I'm using Harma Retros in the phono and line stages with standard JJs in the power supply. I'm happy enough with how mine sounds.

[worrasf]

Mine has 5 ECC83s :scratch:

I'm happy enough with how mine sounds.

... and that's all that matters [emoji1]

[Sondekker]

Yes mine originally had five ECC83's until it was modified by Glenn to cathode follower configuration such that it would drive my low impedance SS power amp. Accordingly, it now uses a 12bh7 in the line stage.

I think I've heard said that Glenn likes the 12bh7 valve.

[Jimbo]

Yep - Standard Croft 25R has two ECC83 phono stage, 1 ECC83 linestage and 2 ECC83 regulation stage.

Any other configuration is because Glenn has done something a bit special:eyebrows:

[hayche]

Try a ECC82 in the series 7. It makes my integrated positively violent.