NOS valves in a Croft preamp. A 'wow' moment!

[pankon]

Apart from the two ECC83 for the phono stage (which have now been occupied by the NOS Tesla E83CC), there are also three other valves, which according to Glenn also affect the phono stage. Namely they are:

1x GE 6463 83-22 33173
1x Sovtek 7025/12AX7WA 0810
1x English electric valve 7709 CV4048 KB/QG

I wonder whether anyone thinks I could upgrade any of the above-mentioned valves with NOS ones, which can make a difference. Any suggestions?

Cheers

[pankon]

Yes, beyond the 'techie' questions, comments and discussions, I have to say that when listening to Van Morrison's Caravan (from the 'In Concert' 1973 record) makes me rock my head, tap my feet, and sing along. Isn't that all what hi-fi is all about? Enjoying the music as if you were there...!

And yes, the NOS Tesla E83CC did play their part in plunging deeper into the music!

(Oops, Caravan just ended. Let's spin it once more -))

[OD1]

I had a brief 2 hr listen to the Teslas yesterday, and the diffs I could hear vs my 50+ hour Genalex tubes were subtle, mainly in the midrange. Having said that, I usually take a while to notice diffs when I make changes, (with the exception of Speakers) so will report back in the next few weeks.

My main concern when comparing kit is I am unsure if I am listening correctly, and what I should be focusing on (currently I listen for extra detail, or little subtle sounds not heard previously)

For Example I think the stock JJ's in my Croft sound good enough that I would have been happy to leave them in situ if I could not change them.

Maybe my listening levels are too low (peaking roughly 89db @ 2.5metres), or my speakers need rearranging ?

[pankon]

Hi Oliver,

thanks for the feedback. I guess you will need to give your NOS Teslas a few hours to break in and settle. Perhaps this may also allow you to appreciate any differences in the sound (good and bad ones).

For me, the differences of my NOS Tesla E83CC from the previous stock valves (NOS HRS and Ei ECC83) were immediate and quite positive. More clarity, detail, separation, fluidity, extension, but most importantly more realism. This is especially noticeable in vocals, which make you think that you have the artist in front of you.

Now, to ('reasonable') people who are not into hi-fi and its nuances, the differences I mentioned above may be barely noticeable, if at all. But the differences are indeed there, and it's not my imagination or wishful thinking -)).

I had a brief 2 hr listen to the Teslas yesterday, and the diffs I could hear vs my 50+ hour Genalex tubes were subtle, mainly in the midrange. Having said that, I usually take a while to notice diffs when I make changes, (with the exception of Speakers) so will report back in the next few weeks.

My main concern when comparing kit is I am unsure if I am listening correctly, and what I should be focusing on (currently I listen for extra detail, or little subtle sounds not heard previously)

For Example I think the stock JJ's in my Croft sound good enough that I would have been happy to leave them in situ if I could not change them.

Maybe my listening levels are too low (peaking roughly 89db @ 2.5metres), or my speakers need rearranging ?

[pankon]

The NOS Tesla E833CC in the phono stage of my Croft SuperMicroII-R have been a revelation for me. Now the question is what make of ECC83 to use in the regulation stage. Brimar? Tesla? Philips? Mullard?

Open to suggestions... -))

Thanks in advance!

[OD1]

My Tesla's now have 30+ hours use, they are indeed pretty special in my Croft. The main differences (vs my Genelex reissues) I have noticed are as follows:

Images appear more solid & in focus, (i.e Marvin Gaye was dead centre of my speakers when I played "Lets Get It On" and more "in the room" than before, in fact I could close my eyes & almost convince myself that he WAS in my room )

Cymbals have more shimmer / decay, and I could hear subtle sounds deeper in the mix. In fact, I swear I thought I heard the studio door shutting during "Freddy Freeloader" from Kind Of Blue

The above differences were subtle, but has added to my musical enjoyment, which is the point of tube rolling in my book

I'm off know to see (hear) if Sade can tell me "your love is king" in my room

[OD1]

The NOS Tesla E833CC in the phono stage of my Croft SuperMicroII-R have been a revelation for me. Now the question is what make of ECC83 to use in the regulation stage. Brimar? Tesla? Philips? Mullard?

Open to suggestions... -))

Thanks in advance!

Pankon,
I use Nos Mullard ECC83's in my Croft pre, but have not listened to alternatives yet !

[pankon]

Oliver,

I fully confirm your comments. The Teslas offer more clarity and more detail, but in an organic manner, not because they are artificially boosting treble. They make records sound so more convincing. Impossible to go back to other, lesser valves in the phono stage...

My Tesla's now have 30+ hours use, they are indeed pretty special in my Croft. The main differences (vs my Genelex reissues) I have noticed are as follows:

Images appear more solid & in focus, (i.e Marvin Gaye was dead centre of my speakers when I played "Lets Get It On" and more "in the room" than before, in fact I could close my eyes & almost convince myself that he WAS in my room )

Cymbals have more shimmer / decay, and I could hear subtle sounds deeper in the mix. In fact, I swear I thought I heard the studio door shutting during "Freddy Freeloader" from Kind Of Blue

The above differences were subtle, but has added to my musical enjoyment, which is the point of tube rolling in my book

I'm off know to see (hear) if Sade can tell me "your love is king" in my room

[pankon]

Well, the Tesla E83CC seem to be unbeatable in the phono stage of the Croft preamp. They are in their own league.

With respect to the ECC83 valve for the regulation, I've tried quite a several NOS alternatives, such as Philips JAN ECG, Brimar ECC83, Mullard ECC83, Mullard CV492. I think that the CV492 performed better than the rest, providing sufficient detail, but with fluidity and naturalness.

At the same time, I changed the stock JJECC83S of my Series7 amp with a Mullard CV492 and that made also significant overall improvement, providing more body and dynamics, as well as a bigger and more detailed soundstage.

I think I am getting there with my valve-rolling. I am quite happy with the result.

It is quite rewarding to be able to improve the sound of the existing amps just by changing one or more valves.

[Gibo69]

Hello pankon,
Which version of the E83CC you have on your preamp?
The frame grid version (code 37) or the NON frame grid one (code 32) ?

Has anybody tried the frame grid one ?