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

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Originally Posted by AlexM

I have three NOS Tesla E83CC in the phono stage of my CJ ET3, and they are very good indeed. I think we need to introduce a little perspective - these valves will perform very well but we are talking about a reasonably subtle improvement if you comparing NOS to NOS (or new-new). We usually think they are very much better compared new to old, tired valves plus a big slice of expectation bias. Nice dimensionalality, and clean, neutral tone, with good detail are characteristics, but I have some Ei 12AX7 which are almost as good sounding and long lived too (if they survive initial burn-in/early life failure!)

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Indeed Alex and a good point about the ageing aspect.

To add a little technical meat to the bones of this thread... much is likely to depend on the exact use to which a valve is put, its biasing, and also power supply voltages. Hence a valve which gives great subjective results in one amp may be not so good in another make or a different position. As far as gain goes well the gain of a triode (mu) is one aspect that is fairly well controlled in manufacture and for a ECC83 should be 100. Actual gain depends much on surrounding circuitry and mu is the maximum theoretically achievable from the valve itself. In the case of pre amps using negative feedback (the majority) the overall gain will be set by the feedback and only slightly effected by the choice of valve... there are some variants with a bit more than standard gain, usually intended for guitar amps in order to give more distortion/overdrive.

Hi Alex,

my Croft SuperMicroII (R-spec) had the initial stock valves since 1989 and until a few days ago, when I replaced the two phono ECC83 valves (NOS HRS and Ei) with NOS Tesla E83CC. Right from the start, the improvement was undeniable. And I hope it is going to become even bigger, as the Tesla valves break in.

Quote:

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Originally Posted by AlexM

I have three NOS Tesla E83CC in the phono stage of my CJ ET3, and they are very good indeed. I think we need to introduce a little perspective - these valves will perform very well but we are talking about a reasonably subtle improvement if you comparing NOS to NOS (or new-new). We usually think they are very much better compared new to old, tired valves plus a big slice of expectation bias. Nice dimensionalality, and clean, neutral tone, with good detail are characteristics, but I have some Ei 12AX7 which are almost as good sounding and long lived too (if they survive initial burn-in/early life failure!)

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And because a picture is a thousand words, I am publishing a photo of my SuperMicro internals...

Attachment 17605

Oliver,

out of curiosity, the NOS Teslas you have ordered are ECC83 or E83CC?

Thanks
P.

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Originally Posted by OD1

Thanks Guys,
I have ordered a matched pair from Mullardman, will update (if ok with you Pankon ?) in this thread once received.
I think I will have to resist looking in on Aos for at least 3 months, it is hitting my pocket HARD :):D
At least my ears are enjoying the journey ;)

Now where did I hide my screwdriver to open the Croft ?

Oliver

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Quote:

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Originally Posted by pankon

Oliver,

out of curiosity, the NOS Teslas you have ordered are ECC83 or E83CC?

Thanks
P.

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Pankon,
They are E83CC, arrived yesterday evening :)
I will put them in later today (after I do my chores !!!!)

Oliver, I am sure you are going to enjoy your Tesla valves! They made a real difference in my preamp.

And if you find some time, it would be great to post one or two photos of your new valves.

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Originally Posted by OD1

Pankon,
They are E83CC, arrived yesterday evening :)
I will put them in later today (after I do my chores !!!!)

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I bought my Tesla E83CC from Peter at Edicron, who was great to deal with and prices were quite reasonable. '33' factory code I believe too, which are the ones to have. They may still have some stock

Sent from my Nexus 7 using Tapatalk

So, any impressions, Oliver?

Any photos perhaps?

Enjoy!

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Originally Posted by OD1

Pankon,
They are E83CC, arrived yesterday evening :)
I will put them in later today (after I do my chores !!!!)

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Quote:

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Originally Posted by pankon

Oliver, I am sure you are going to enjoy your Tesla valves! They made a real difference in my preamp.

And if you find some time, it would be great to post one or two photos of your new valves.

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Hi Pankon,
Before I put the Teslas in, I visually checked them vs the stock JJ's. The flasher is darker & the tops are flatter, which according to the Jac Music website denotes a proper Tesla valve. Mine shows "32" under the E83CC code, which tallies with James' description of his. I have only had a brief listen at low volume, but will check them out on Sunday.
I did have a listen for tube noise with the pre turned up to max & all good.

Oliver

Super! We will be waiting for your impressions.

P.

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Originally Posted by OD1

Hi Pankon,
...
I did have a listen for tube noise with the pre turned up to max & all good.

Oliver

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