Croft 25R and 7R tubes

[Gibo69]

As an extremely happy owner of the combo Croft 25R /7R (thanks Dave !) + Harbeth SHL5 plus, I think I am set for eternity :).....the only upgrade will be for a new TT in the not too distant future, suited for a Decca cartridge( NA Hypespace or Dais ?)....actually I have a Thorens TD 320 with an Ortofon 2M Black.
Anyway....reading this forum, I saw many Croft owners changing the standard JJ ECC83 tubes in the phono stages with different types of tubes...
I was able to get two NOS TESLA E83CC tubes that I plan to put in the phono stages.
Apart from the phono stage, do changing tubes in the line and regulation stages have a big impact ?

What are your experiences in tube rolling with the 7R ?
I know it has two ECC83... I presume one is for the regulation stage and the other for the line stage ?
Any "to do/not to do" suggestions ?
Thanks !
Happy new year !

[hifi_dave]

No advice re tubes, just thought I'd confirm that the Nottingham Analogue turntables and arms were made for Decca cartridges.

[Gibo69]

Hello Dave ,
Yep....that's why I have my eyes on them....
Do you think the Ace Space 12" arm is good or should go for the Anna arm ?

[hifi_dave]

The 12 inch Ace Space arm is great but of course the Ace Anna is better. Both were designed using various Decca cartridges. If you can squeeze in a 12 inch arm you will gain an ease and clarity which 9 and 10 inch arms can't quite manage.

[Jimbo]

Hi Aris, yes changing tubes in the regulation stage also helps but the linestage is critical as the phono stage runs through this. I have had my linestage changed to the RS linestage which now accommodates a 12BH7a tube (RCA) which is a good upgrade. Generally NOS tubes throughout are better than the jj.

Regarding the 7R, again changing the tubes for NOS brings improvement to the input valve stage and Mullard are considered good in this position or Brimar. Basically it is a matter of voicing the Croft amps to what you like to hear. Warm and valvey or crisp and clear and everything in between.

I use NOS Teslas throughout my preamp and an RCA long plate 12BH7a in the linestage. In the power am I use a GE JAN 5751.

[Gibo69]

The 12 inch Ace Space arm is great but of course the Ace Anna is better. Both were designed using various Decca cartridges. If you can squeeze in a 12 inch arm you will gain an ease and clarity which 9 and 10 inch arms can't quite manage.
Thanks Dave....we'll see when it's time to do it.

[Gibo69]

Hi Aris, yes changing tubes in the regulation stage also helps but the linestage is critical as the phono stage runs through this. I have had my linestage changed to the RS linestage which now accommodates a 12BH7a tube (RCA) which is a good upgrade. Generally NOS tubes throughout are better than the jj.

Regarding the 7R, again changing the tubes for NOS brings improvement to the input valve stage and Mullard are considered good in this position or Brimar. Basically it is a matter of voicing the Croft amps to what you like to hear. Warm and valvey or crisp and clear and everything in between.

I use NOS Teslas throughout my preamp and an RCA long plate 12BH7a in the linestage. In the power am I use a GE JAN 5751.

Thank you very much for the explanation Jimbo.
The 7r has two ECC83, you basically put the GE in both sockets ?
Regarding Mullard...do you mean a tube like the M8137 Cv4004 ?
Thanks !!

[Jimbo]

Thank you very much for the explanation Jimbo.
The 7r has two ECC83, you basically put the GE in both sockets ?
Regarding Mullard...do you mean a tube like the M8137 Cv4004 ?
Thanks !!

The GE 5751 will lower the power a touch but I think you get a better sound and yes you need 2. I think the Mullard is the CV4004.

Good luck

[Gibo69]

The GE 5751 will lower the power a touch but I think you get a better sound and yes you need 2. I think the Mullard is the CV4004.

Good luck

Thank you very much !

[Elephantears]

Great set up you have there. I think the 25R/7R has a perfect synergy with SHL5Plus. I've not tube rolled that much with the 7R (which I've been borrowing for a while), but a Brimar ECC83 works well. Regarding your TT search, I really like the 12" Ace Space and recommend it. I'm currently using it with a Miyajima cart and it works nicely. I may end up selling it if I get hold of a Fidelity Research tonearm, since they are supposed to be the perfect arms for Miyajima. If so, I could let you know.

[Gibo69]

Great set up you have there. I think the 25R/7R has a perfect synergy with SHL5Plus. I've not tube rolled that much with the 7R (which I've been borrowing for a while), but a Brimar ECC83 works well. Regarding your TT search, I really like the 12" Ace Space and recommend it. I'm currently using it with a Miyajima cart and it works nicely. I may end up selling it if I get hold of a Fidelity Research tonearm, since they are supposed to be the perfect arms for Miyajima. If so, I could let you know.

Hello Elephantears,
Thanks for the suggestion regarding the 7R.
Any specific model of Brimar you have in mind ?
If you decide to sell the Ace Space arm I am surely interested.
Let me know.
Best regards

Thank you very much.

[Gibo69]

The GE 5751 will lower the power a touch but I think you get a better sound and yes you need 2. I think the Mullard is the CV4004.

Good luck

Jimbo,
May I ask you which version of the GE JAN 5751 you use ?
I saw a post in this forum regarding Tubes for Croft Amps, that suggested a "GE JAN 5751 red tip triple mica black plate"....
How yo recognize this valve ? Are there lot of fakes around ?
Thanks.

[Jimbo]

Jimbo,
May I ask you which version of the GE JAN 5751 you use ?
I saw a post in this forum regarding Tubes for Croft Amps, that suggested a "GE JAN 5751 red tip triple mica black plate"....
How yo recognize this valve ? Are there lot of fakes around ?
Thanks.

Mine is a JAN GE 5751 valve. It is available from Watford valves UK.

[Gibo69]

Mine is a JAN GE 5751 valve. It is available from Watford valves UK.
Is this one ? :
https://www.watfordvalves.com/product_detail.asp?id=681

Thanks Jimbo

[Jimbo]

Is this one ? :
https://www.watfordvalves.com/product_detail.asp?id=681

Thanks Jimbo

Hi Aris, that is the one. Just compared it against a 1962 RCA 5751 and I think the JAN GE 5751 is better!

[Gibo69]

Hi Aris, that is the one. Just compared it against a 1962 RCA 5751 and I think the JAN GE 5751 is better!

Thank you very much.