Croft 25R+

[Jimbo]

Just a few pics for Croftphiles who would like to see what the internals of Croft 25R with upgraded line stage.
http://i326.photobucket.com/albums/k424/Spendorsp2/image_zpsmzwe7plx.jpeg (http://s326.photobucket.com/user/Spendorsp2/media/image_zpsmzwe7plx.jpeg.html)
http://i326.photobucket.com/albums/k424/Spendorsp2/image_zpspnsekyyy.jpeg (http://s326.photobucket.com/user/Spendorsp2/media/image_zpspnsekyyy.jpeg.html)
http://i326.photobucket.com/albums/k424/Spendorsp2/image_zpsy0mglvna.jpeg (http://s326.photobucket.com/user/Spendorsp2/media/image_zpsy0mglvna.jpeg.html)

[wee tee cee]

fithy hi fi porn!!!-

was over at Brians place recently and heard his croft pre/power- sublime!!!

[Bigman80]

Wow !!

Sent from my EVA-L09 using Tapatalk

[Elephantears]

How is this different to the standard 25R? Interested to know about any particular modifications and what difference you felt they made.

[Jimbo]

How is this different to the standard 25R? Interested to know about any particular modifications and what difference you felt they made.

The line stage is from the 25RS. Bit more open sound and slightly more dynamic.

[Frazeur1]

Thanks for sharing the pics with us James! I really should look to get my 25 upgraded to "R" spec at some point!

[Audio Al]

Lots of gubbins inside , very nice :eyebrows:

[Jimbo]

Thanks for sharing the pics with us James! I really should look to get my 25 upgraded to "R" spec at some point!

If you do get it upgraded Tim, maybe get the linestage done at the same time?

[Elephantears]

The line stage is from the 25RS. Bit more open sound and slightly more dynamic.

It looks the same as the 25R in essentials, although there do look to be some different resistors etc. I'm not an expert, I should add. But the key to the RS is the separate PSU. Just trying to ascertain what exactly Glenn has done to this, since I have an R myself.

[Jimbo]

It looks the same as the 25R in essentials, although there do look to be some different resistors etc. I'm not an expert, I should add. But the key to the RS is the separate PSU. Just trying to ascertain what exactly Glenn has done to this, since I have an R myself.

Sorry Andy i should have been a bit more specific. I was in a bit of a rush last night.

So what Glenn has done is change the line stage resisitors to non inductive type as well as reconfiguring the circuitry to work with the 12BH7a valve type.These are key elements in the RS although as you rightly mention the RS has a separate PSU. I believe the change to this linestage is more significant than the separate PSU in terms of SQ but I cannot be sure unless I could get the two box 25R and listen back to back against mine. I expect the separate PSU lowers the noise floor as it is situated well away from the valves causing less interference?

[Frazeur1]

It doesn't appear to be a full-on 25RS here, but maybe the "S" stands for "special"? I could be a bit wrong there, but either way, looks to be definitely some differences in the resistors. Never mind, I see James has replied.

Yes, I should do the line stage upgrades as a minimum possibly, as I am still phono-less at the moment, oh the horrors! Anyway, well done James!

[Jimbo]

It doesn't appear to be a full-on 25RS here, but maybe the "S" stands for "special"? I could be a bit wrong there, but either way, looks to be definitely some differences in the resistors. Never mind, I see James has replied.

Yes, I should do the line stage upgrades as a minimum possibly, as I am still phono-less at the moment, oh the horrors! Anyway, well done James!

You have access to loads of fantastic tube suppliers in the states Tim so should be able to trick a 25R out with some very good NOS tubes. I particularly recommend a NOS RCA 12BH7a 1950,s or early 60's in the linestage if you can get one?

[Frazeur1]

Thanks for the recommendations James. I haven't ventured too far down that rabbit hole yet, but it is only a matter of time-without getting too crazy. I have been looking at various 12AX7's for my line stage as things stand now. Biding some time yet, work is killing me right now! You know what they say, all work and no play...

[Jimbo]

I thought I had come to the end of my tube rolling with the 25R but as I had read so many good reports regarding Brimar valves I though I would try one.

It was supplied by Anthony (Tube Distinctions) and I must say he let be have a superb example. This was an unused NOS Black plate 12BH7 which is used in my line stage. After 20 hours run in I can must say this is by far the best valve of this type I have used in this position. My previous reference was an NOS RCA 12BH7a which gave wonderful clarity but the Brimar goes further in this respect. However it's ability to create a huge soundstage with wonderful layering of detail is amazing. Helen and myself have both noticed not only details that lay obscured but also an extra vivid dimension especially to vocals where acoustic nuances have been revealed.


What a fabulous valve and a big thanks to Anthony for his excellent service which also included testing the valve and super speedy delivery -next day!

[brian2957]

Would this valve be suitable for the standard 25 James ?

[Jimbo]

Would this valve be suitable for the standard 25 James ?

Hi Brian, the 12BH7a valve is not really suitable for the line stage on the standard 25 or 25R as this position is optimised for a ECC 83. The circuitry needs to be changed to use a 12BH7 valve.

[brian2957]

Thanks mate :)