Croft valve rolling question

[Bigbird]

Hi guys hope your all well.

Im after a bit of advice from any Crofties or valve experts.

Ive got the croft 25r with upgraded linestage
And the 7r monos.

After speaking with a few people the unanimous decision was that rolling the linestage 12bh7A will alter the sound the most and that the 50s NOS RCA valves seem to be most peoples go to choice for best of the best valve. It already has a nice nos Sylvania in there but i fancy a bit of fun to see if i can taylor the sound a bit more.

Others also recommended that swapping out the line in valves on the monos has a nice effect. To get the clean detailed sound that i like i had been recommended the Nos GE 5751 in this position BUT luckily i took the top off to have a check as the valves in this position are also 12bh7A not ecc83 or variant types.

Ive pulled the trigger on a nice(but expensive)pair of 1956 RCA black plates, NOS and matched and super strong. I will also pick up one more at next pay cheque to complete the trio that i need.

Anyway enough rambling my question is, has anybody tried any different valves in the other positions?
The rest of the valves in the pre are a Mullard 85A2 and 2 JJ ECC83S

And one ECC83S and one 85A2 in the two mono.

Will changing any of these effect the sound or are they just for power regulation? Its all new to me so not sure, and dont want to spend lots more on top NOS tubes if its not going to make a difference.

Thanks for any help

Karl


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[Jazid]

The 85A2 won't, it's a voltage stabilizer, the others might but the JJ are established favourites on the forums so you'd need to expect different rather than 'better' sound by rolling them.
The obvious choices are box plate Mullard and pre JJ era Tesla E83CC. I'd wait to see how the 12BH7a work out first though..

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[Wakefield Turntables]

The 85A2 won't, it's a voltage stabilizer, the others might but the JJ are established favourites on the forums so you'd need to expect different rather than 'better' sound by rolling them.
The obvious choices are box plate Mullard and pre JJ era Tesla E83CC. I'd wait to see how the 12BH7a work out first though..

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You'd be surprised, I've heard many croft luminaries claim rolling 85a2 does change sonics!!!

[fiddlemaker]

Others may well disagree, but I've found no benefit in changing the stock JJ ecc83s's in the power supplies.

[worrasf]

Hi guys hope your all well.

Im after a bit of advice from any Crofties or valve experts.

Ive got the croft 25r with upgraded linestage
And the 7r monos.

After speaking with a few people the unanimous decision was that rolling the linestage 12bh7A will alter the sound the most and that the 50s NOS RCA valves seem to be most peoples go to choice for best of the best valve. It already has a nice nos Sylvania in there but i fancy a bit of fun to see if i can taylor the sound a bit more.

Others also recommended that swapping out the line in valves on the monos has a nice effect. To get the clean detailed sound that i like i have been recommended the Nos GE 5751 in this position BUT luckily i took the top off to have a check as the valves in this position are also 12bh7A not ecc83 or variant types.

Ive pulled the trigger on a nice(but expensive)pair of 1956 RCA black plates, NOS and matched and super strong. I will also pick up one more at next pay cheque to complete the trio that i need.

Anyway enough rambling my question is, has anybody tried any different valves in the other positions?
The rest of the valves in the pre are a Mullard 85A2 and 2 JJ ECC83S

And one ECC83S and one 85A2 in the two mono.

Will changing any of these effect the sound or are they just for power regulation? Its all new to me so not sure, and dont want to spend lots more on top NOS tubes if its not going to make a difference.

Thanks for any help

Karl


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Hi Karl
I have a very similar setup to yours (25RS and 7monos) which I have had for a good few years and as you might expect have done a fair bit of tube rolling.

My impressions are:

The 7's (I know yours are 7R's) are pretty much immune to tube rolling benefits. Mine came with JJ ecc99 gold pins and I stick with them.

With the line stage I have settled on a NOS Raytheon 12BH7. I found the GE's dull and flat. RCA's very variable the NOS long black plates were very nice but the grey plates a bit so so. There are many incarnations of the Sylvania (red, yellow, green print etc). I have a pair of the latter but am yet to try. Glenn seems to favour the Westinghouse 12BH7 which I'm pretty sure is very similar to the Raytheon.

In the phono stage it really really depends on how you want to tune the sound. FWIW I pretty much settled on NOS Siemens ecc83's. I also use these in the regulator section as they do make an audible difference. 1960's RCA black plate 5751's are very mellow (I have 2 pairs) Philips Miniwatts have a lush midrange and dead quiet. If you want to go "left field"then the Psvane T2 12AX7's are very quiet with no signature of their own. Totally uncoloured. Not tried Mullards in the 25RS but I found them too warm for my taste in my old Vitale.

As always it's down to personal taste - don't let anyone tell you one valve is "better" than another. All you can do is listen and decide if they float your boat.

Steve

[fiddlemaker]

Hi Karl


The 7's (I know yours are 7R's) are pretty much immune to tube rolling benefits. Mine came with JJ ecc99 gold pins and I stick with them.



Steve

I found that a nice pair of 12BH7a's in the 7R mono input stages were much better than the stock ECC99's, and actually would say that in my system they made a more significant improvement than replacing any of the preamp valves.

As Steve says at the end of his post it's all down to personal taste. :)

[Jazid]

You'd be surprised, I've heard many croft luminaries claim rolling 85a2 does change sonics!!!Well fair enough, I agree it's more likely to have an effect on sonics than changing the power plug [emoji16]

Also, if the regulator is out of spec then voltage has drifted, or it won't keep regulation, either of which could be audible, or indeed one valve could be noisier than another, so point taken [emoji1787]

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[Bigbird]

Thanks for all the replies gents.

This is why i put a thread up as there are so many different views on this situation and also so many different incarnations of the croft amps its hard to get a straight answer.
Its still a bit inconclusive for me now haha. Some say yes, some say no.

I suppose the only way really is to try myself. Unfortunately some of these valves are scarce and eye wateringly expensive nowadays and to buy a few to find out you dont like them or they do bugger all is not ideal.

I think enough of you have said it does make enough difference for me to give it a go . As you know at this stage of the game it’s usually small improvements anyways and every little helps.

I dont have the phono in mine as i use a whest 2.2 so no valves to worry about there.

From any of your experiences, did you find that the power regulation valves (ECC83S)made a more audible difference to the sound than voltage regulation(85a2)?

The silver mullard 85a2 that are currently in there do look old as the lettering has mostly come away but its hard to be sure what type they are and if they are the stock standard ones glenn supplies or were upgraded by the previous owner??? Any recommendations for 85A2 valves ??

Also can any of you recommend a nice 12bh7A with a clean ,clear,detailed sound? im trying to avoid too warm as i like the ‘hifi’ sound myself.

I think i will take out the existing NOS GE 12bh7A from the monos and use the NOS 50s RCA long black plates in there as they are perfectly matched,dated and balanced and it seems a shame to break them up . i will track down something else for the preamp linestage. I will definitely try one in the linestage first though incase they make a bigger difference there.

I know that a lot of these tubes will come down to tastes and may well just be different , but different can also be better if its giving you the sound that you are trying to achieve.

Thanks again

Karl


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[Jazid]

85a2 and most (at least Mullard) regulator valves look ancient when they are not even middle aged. Not a cause for concern if they look like salvage from the Torrey Canyon, beauty is more than skin deep!

Can't speak for valves in these particular circuits, though I did have a series 7 power amp. Notably Glenn's choices have always been exemplary and his valve matching is impeccable, so whatever he put in will be irreproachable technically and sonically. So saying he used to use the valves I referred to earlier in his line stages so they have provenance, though his stocks may have dried up.

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[Antinchip]

I got my 7R's from Glenn via Adrian at Audioflair in late 2016. They came with;

RCA 12BH7A stamped "USA"
Mullard 85A2
JJ ECC83S

The distilled discussion as to valve rolling with Adrian and his recommended valve supplier, Matt Francesco, was;

For the 12BH7A, alternatives might be Tungsol grey or black plates having more "grip" but the RCA's with more "presence". Another comment; "The 7R's being very grippy anyway I can see why some go for the RCA". Otherwise GE with a "dryer, cleaner" sound. I didn't audition the alternatives and stuck with the RCA's.

For the 85A2, Mullard was deemed "best" so I stuck with that.

For the ECC83S, NOS Mullard ECC83 were recommended for a "more noticeable uplift". I auditioned these and they stayed put.

I have been very much enjoying the 7R's, now with a more recently acquired Micro 25R (2 x Electro-Harmonix 12AX7, 3 X JJECC83S, Mullard 85A2), all revealing music with great presence, life, detail and transparency whilst not dry or clinical. I have an RIAA-R, which seems to offer great opportunity for valve rolling. Can't quite remember the original valve compliment but it is now;

Tungsol 12BH7A grey plate
2 x Tesla E83CC
2 X Mullard ECC83
Mullard 85A2

Since I have the RIAA-R my next step is to get Glenn to remove the phono stage from the 25R and upgrade to the 25RSLS linestage (perhaps with some other mod's). I will probably start with Glenn's USA RCA12BH7A's and see how it goes from there. Should hopefully be done in August.

Have fun.

[Jimbo]

I was not aware the 7R power amps used the 12BH7a valve in the input stage. I would use some nice NOS Brimars in this position if I were to valve roll in this position.

Interestingly I use standard JJ Tesla ECC83 valves I the regulation stage of my 25R as they seem to work very well in this position. The beat my NOS Tesla valves in the regulation stage. However the Phono stage has to be Teslas for me. I put them up against everything I could get my hands on including Telefunkens and they came out top. Very clear powerful sound with great top end detail and nice full midrange.

Of all the 12BH7a valves I have used the NOS RCA have been the best all round sound. I am using Brimar at the moment which have a powerful darker sound but balance the Teslas nicely.

[fiddlemaker]

I was not aware the 7R power amps used the 12BH7a valve in the input stage. I would use some nice NOS Brimars in this position if I were to valve roll in this position.

Interestingly I use standard JJ Tesla ECC83 valves I the regulation stage of my 25R as they seem to work very well in this position. The beat my NOS Tesla valves in the regulation stage. However the Phono stage has to be Teslas for me. I put them up against everything I could get my hands on including Telefunkens and they came out top. Very clear powerful sound with great top end detail and nice full midrange.

Of all the 12BH7a valves I have used the NOS RCA have been the best all round sound. I am using Brimar at the moment which have a powerful darker sound but balance the Teslas nicely.

Hi Jim, only the 7R monos use the 12bh7 (or ecc99) as standard.

[Jimbo]

Hi Jim, only the 7R monos use the 12bh7 (or ecc99) as standard.

Thanks John, I never knew that. I am sure the first 7r had ECC83s.

[Jazid]

Hi Jim, only the 7R monos use the 12bh7 (or ecc99) as standard.My 7r stereo amp did as well, but it was 'Tannoy spec' so an upgraded rather than standard model.

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[Bigbird]

I got my 7R's from Glenn via Adrian at Audioflair in late 2016. They came with;

RCA 12BH7A stamped "USA"
Mullard 85A2
JJ ECC83S

The distilled discussion as to valve rolling with Adrian and his recommended valve supplier, Matt Francesco, was;

For the 12BH7A, alternatives might be Tungsol grey or black plates having more "grip" but the RCA's with more "presence". Another comment; "The 7R's being very grippy anyway I can see why some go for the RCA". Otherwise GE with a "dryer, cleaner" sound. I didn't audition the alternatives and stuck with the RCA's.

For the 85A2, Mullard was deemed "best" so I stuck with that.

For the ECC83S, NOS Mullard ECC83 were recommended for a "more noticeable uplift". I auditioned these and they stayed put.

I have been very much enjoying the 7R's, now with a more recently acquired Micro 25R (2 x Electro-Harmonix 12AX7, 3 X JJECC83S, Mullard 85A2), all revealing music with great presence, life, detail and transparency whilst not dry or clinical. I have an RIAA-R, which seems to offer great opportunity for valve rolling. Can't quite remember the original valve compliment but it is now;

Tungsol 12BH7A grey plate
2 x Tesla E83CC
2 X Mullard ECC83
Mullard 85A2

Since I have the RIAA-R my next step is to get Glenn to remove the phono stage from the 25R and upgrade to the 25RSLS linestage (perhaps with some other mod's). I will probably start with Glenn's USA RCA12BH7A's and see how it goes from there. Should hopefully be done in August.

Have fun.

That will be some system when youre done matey. Do you know what other mods can be done after its been turned into full blown 25RLS??
I think when the time comes to send mine back to glenn to go full blown RS id like to max it out completely with any extra mods so that im not sending it back and forth from Oz everytime an upgrade is imminent

I think i too will use the RCAs ive ordered in the monos in place of the GE that are currently in there.


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[Bigbird]

I was not aware the 7R power amps used the 12BH7a valve in the input stage. I would use some nice NOS Brimars in this position if I were to valve roll in this position.

Interestingly I use standard JJ Tesla ECC83 valves I the regulation stage of my 25R as they seem to work very well in this position. The beat my NOS Tesla valves in the regulation stage. However the Phono stage has to be Teslas for me. I put them up against everything I could get my hands on including Telefunkens and they came out top. Very clear powerful sound with great top end detail and nice full midrange.

Of all the 12BH7a valves I have used the NOS RCA have been the best all round sound. I am using Brimar at the moment which have a powerful darker sound but balance the Teslas nicely.

I wasnt either Jim, bloody good job i checked before i spent 100 quid on some nice 5751’s.

I may try a NOS tungsol in the pre.. any experience with them yourself mate?

Failing that i will just track down another 56 RCA if i like the sound of the others. Might get some nice synergy with 3 of them in there?


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[Antinchip]

Karl,

What I will be going for is removal of the phono stage and replacement with the 25RSLS line stage to have one 12BH7A per channel giving four line inputs. Perhaps not "full blown" since it will not have the separate PSU, I have too many boxes already.

As I understand it from my e-mail exchanges with Glenn, other options include;
Paper in oil output caps.
Better phono sockets.
Better pots.
But he did go on to write "Etc. The sky's the limit....". Maybe that's another conversation.

Cost is clearly a factor so I am keeping my options open whilst saving up until Glenn is ready to do the work in August.

Have fun.

[Bigbird]

Karl,

What I will be going for is removal of the phono stage and replacement with the 25RSLS line stage to have one 12BH7A per channel giving four line inputs. Perhaps not "full blown" since it will not have the separate PSU, I have too many boxes already.

As I understand it from my e-mail exchanges with Glenn, other options include;
Paper in oil output caps.
Better phono sockets.
Better pots.
But he did go on to write "Etc. The sky's the limit....". Maybe that's another conversation.

Cost is clearly a factor so I am keeping my options open whilst saving up until Glenn is ready to do the work in August.

Have fun.

Ah ok I understand what your saying. Mine is already at that point so the next step is seperate PSU and beyond. Maybe i will try get hold of glenn and ask him myself.

You dont have his email do you please? Ive tried emailing him recently with no reply so maybe im using the wrong address?

Thanks

Karl


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[worrasf]

Here you go

glenn@croftacoustics.co.uk

glen.croft@btinternet.com

I think he may be on leave as I am waiting for him to get back to me on parts availability for the very 25RS upgrade under discussion

Steve

[Bigbird]

Here you go

glenn@croftacoustics.co.uk

glen.croft@btinternet.com

I think he may be on leave as I am waiting for him to get back to me on parts availability for the very 25RS upgrade under discussion

Steve

Ah ok that may explain it then. Thankyou buddy appreciate that.

Bet you cant wait for that upgrade??


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[Bigbird]

https://uploads.tapatalk-cdn.com/20190520/eaca0d965771a1630f6c204847b3803e.jpg

Little piccy of the 56 RCA’s i took the plunge on. Anyone tried these?


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[worrasf]

https://uploads.tapatalk-cdn.com/20190520/eaca0d965771a1630f6c204847b3803e.jpg

Little piccy of the 56 RCA’s i took the plunge on. Anyone tried these?


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I used to use RCA long black plate 12BH7's in my Croft Series 4s and found them the "nicest" of the 12 BH7's I tried. I liked them much more than the RCA grey plates. I find a 1960's vintage Raytheon 12BH7 hits the sweet spot in the 25RS line stage.

Steve

[Bigbird]

I used to use RCA long black plate 12BH7's in my Croft Series 4s and found them the "nicest" of the 12 BH7's I tried. I liked them much more than the RCA grey plates. I find a 1960's vintage Raytheon 12BH7 hits the sweet spot in the 25RS line stage.

Steve

Thats good to know. Ive had it on good authority that the 50s RCAs are the best. Can you remember how the raytheon differs? I need to buy one more for my linestage but dont know wether to wait until i hear the RCAs first or take the plunge on something else


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[worrasf]

Thats good to know. Ive had it on good authority that the 50s RCAs are the best. Can you remember how the raytheon differs? I need to buy one more for my linestage but dont know wether to wait until i hear the RCAs first or take the plunge on something else


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In the line stage the Raytheon is more "open and transparent" with better fine detail than the RCA. The RCA has a fuller mid range "bloom" but to my ears the Raytheon suits digital replay better but YMMV.

Steve

[Bigbird]

In the line stage the Raytheon is more "open and transparent" with better fine detail than the RCA. The RCA has a fuller mid range "bloom" but to my ears the Raytheon suits digital replay better but YMMV.

Steve

Hhmmm this has got me thinking now. They are definitely three of the characteristics i like. Although i very rarely play digital music unless I stick spotify on for the missus. (She’s forbidden from the turntable , far to clumsy for that haha)

Can you remember what year and lettering it was Steve?

Thanks


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[worrasf]

Can you remember what year and lettering it was Steve?



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Afraid I can't remember. I bought it from Drew of this parish (user name da2222). He is a fantastic source for guaranteed quality NOS tubes. He's currently got a post on Private Exhibitions for NOS ecc82's but drop him a PM about 12BH7's.

Steve

[Bigbird]

Afraid I can't remember. I bought it from Drew of this parish (user name da2222). He is a fantastic source for guaranteed quality NOS tubes. He's currently got a post on Private Exhibitions for NOS ecc82's but drop him a PM about 12BH7's.

Steve

No worries mate, i actually messaged him last night but he doesnt have any 12bh7A at the moment. Theres a couple of 50s and 60s black plate raytheon available in america for 40-50 usd. Not too badly priced. Might be worth a gamble?


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[worrasf]

You could also consider a Westinghouse 12BH7. There is actually one for sale on AoS at the moment.
https://theartofsound.net/forum/showthread.php?64193-Westinghouse-12BH7a-for-sale

Steve

[fiddlemaker]

No worries mate, i actually messaged him last night but he doesnt have any 12bh7A at the moment. Theres a couple of 50s and 60s black plate raytheon available in america for 40-50 usd. Not too badly priced. Might be worth a gamble?


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I think you'll be absolutely fine with the very nice NOS valves you've got already.
Looking back on my own experience, the only change I'd consider a priority would be swapping any ECC99's that might have been fitted for NOS 12bh7's.
Apart from that if someone were to sneakily replace my carefully selected NOS valves with others I'd rejected, I reckon I probably wouldn't notice the difference.
You can get really hyper about these things when you're "in the zone" and waste an awful lot of time and money.
That's what I reckon, anyway. :)

[Bigbird]

You could also consider a Westinghouse 12BH7. There is actually one for sale on AoS at the moment.
https://theartofsound.net/forum/showthread.php?64193-Westinghouse-12BH7a-for-sale

Steve

Thanks steve i have spoken with Jim and he prefers the RCA valves aswell so i shall see how i go with the ones ive got first


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[Bigbird]

I think you'll be absolutely fine with the very nice NOS valves you've got already.
Looking back on my own experience, the only change I'd consider a priority would be swapping any ECC99's that might have been fitted for NOS 12bh7's.
Apart from that if someone were to sneakily replace my carefully selected NOS valves with others I'd rejected, I reckon I probably wouldn't notice the difference.
You can get really hyper about these things when you're "in the zone" and waste an awful lot of time and money.
That's what I reckon, anyway. :)

This is what im worried about. Are the changes going to be so small that it doesnt warrant all the extra money on posh valves.

I think i will sit tight and see how i go replacing the GE in the monos as the pre has a nice (and pretty expensive according to Blodger of this parish) nos sylvania in it already . Dont want to be wasting precious vinyl money if i dont have too.

Thanks


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[Bigbird]

Just thought id post a quick update on my thoughts on the new valves.

Ive done a lot of experimenting with different combinations tonight and have been absolutely glued to the seat with the results. I really wasnt prepared for it to be such a big improvement with the NOS ‘56 RCA’s but my god they have wiped the floor with the Sylvania and Edichrons.. and i mean wiped, in every single way. So much so ive been sat thinking that if i never did a single thing to the setup from this day forward i would live with it happily forever.

With the law of deminishing returns as you move up the ladder, i honestly think youd have to spend best part of a grand on equipment in relative terms to get this sort of upgrade. Its been that big a difference. And i just thiught it would be a slight change of flavour so to speak.

Firstly i kept the setup the same as its always been with Sylvania in the pre and edi’s in the monos and all sounded as brilliant as it has always done. So, out with the Sylvania and in with one of the new RCA... and bang... from the first few notes i could instantly hear just how much more rich and holographic it sounded. It had a much better tonal balance as well, smoother, more detail, everything just sounded right. Winner!

I didnt want to think i was just tricking myself into justifying the $150 for the 2 valves so after a couple of tracks out came the RCA and back in with the Sylvania.

instantly it sounded flatter, warmer, darker and constricted, even the missus could here it. The same sort of feeling you get when you go from using a decent component of some sort (like a phono stage) to one that isnt quite as good. So back in with the RCA and wow, back with a bang.

Next i wanted to try the new valves in the monos so the sylvania went back in the pre and the RCAs in the monos and that beautifully balanced richness and detail was still there but it retained a bit of the darkness and warmth from the sylvania but none of the flatness, a really nice sounding combo actually , and possibly how it is going to stay for the time being until i hunt down another 56 RCA for the preamp so i have a tri of them in the hotspots.

However the best combo was easily the RCA in the preamp and the NOS edichron in the monos. It was jaw dropping good. The sound just filled the room beautifully. Hopefully with the RCA’s in all three positions it will be able to beat this combo and add a little extra to what is already here.

My final combo will be trying the NOS Edi in the preamp with RCA’s in the monos, but thats for tomorrow as its getting late here in oz.

Anyway conclusions are the 56 RCA are STUNNING and well worth their high price.
Rolling the preamp makes the biggest difference in sound quality BUT the monos also make a substantial difference and should definitely be considered when upgrading valves.

Cheers

Karl https://uploads.tapatalk-cdn.com/20190604/3b13b0fc4912dc761d2c042f84097595.jpg


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[Jimbo]

Nice review Karl and a good to hear the NOS RCA's worked out. They have always been the best valve in my linestage (12BH7a). They seem to do everything just right and some more!

My personal thoughts were that they sounded well balanced from top to bottom without accentuating or loosing out in any area plus they have a lovely holographic aspect which makes the imaging really pop.

I am using a Brimar at the moment but it has a darker tonal quality. I prefer the RCA.

[Opti-cal]

Hi Karl,

my experience mirrors yours above with 50's RCA's. Mine were put into a Micro 25 but I've had similar experiences putting 50's RCA's in plenty of amps. They were the shorter plates but I'd assume the sound signature will at least be similar. I too swapped in some Sylvania's which I know do a fine job in other circuits but it was a night and day comparison.

Just massive full sound front to back, left to right. Rich and detailed.

As you have noticed, biggest difference in pre and pre-sections.

Glad you've found some good'uns

[Bigbird]

Thanks Jim and Chris, massive, rich and holographic they are. Problem is where do you from here?? Surley its only downhill from here?

Time to get saving and focus my efforts on a new tonearm now ive got the amps sussed out.


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