WAD Pre II, cathode follower, a bit bright

[buddam]

Dear all

looking at old posts, this came up: "I suspect part of the clinicity is to do with 6922, it has a tendancy to sound that way".

I have a few questions. Does anyone have experience of a slightly warmer and richer alternative? Are E88CCs identical to 6922? Is the brand an issue (ie does anyne have tube rolling experience?

Alternatively, might it be the 3 5751s in the Phono II?

Thanks

Adrian

[Phil Y]

Hello Adrian,

Could you link to the relevant thread?
It would be much easier to comment if seen in context.

Phil.

[bob orbell]

OK, I have been talking about brightness with Phono II & III, first, do you use any digital sources, IE, CD, and if you do, is the sound from CD bright? or is it just from Phono?, I use CF with active load as Pre and E88CC tubes, is your Phono in stock condition or modified, dose it have the 3.18uS time constant fitted ?. I have made a small change to my Phono III, that brings it much closer to RIAA. Using 5751 tubes does alter the RIAA, and I have found that ECC83 with my small mod is almost bang on. Report back and we will move on. BOB

[Richard]

Bob, you use the CF converted Pre and had a couple of 7308 valves from me - were they for that - and how did you find them?

[bob orbell]

Hi Richard, I use them in a Musical Fidelity X10D buffer after my MF X-RAY CD player, I have just recently tried them in my new Cathode Follower with active load, but returned to two Mullard E88CC gold pin, the 7308 have been fitted back into the MF, X10D, in the X1OD, I can tell no difference between them or any other, but in my Pre the 7308's sound a tad ragged compared to the Mullard. I think we should wait until Adrian comments to my last post, it may be his Phono that is at fault. BOB

[Richard]

Morning Bob, Adrian,

Thanks for your thoughts on 7308. I still have a load along with Russian, Mullard standard and gold pins etc, but nothing to compare them in. I was going to offer Adrian a couple to try but have no handle on their sound. A very general comment would be that I've found military numbers to often sound a little darker/smoother than various civvy versions and thoughts are it may be more rugged construction preventing vibration and colouration.

Adrian asks about 6992/ECC88 valves types. ECC88, 6DJ8, E188CC, 6922, 7308 etc are all interchangeable for hifi but may have different section matching, construction, ruggedness and longevity features as some were military and tested for such. They used to have a reputation for being variable and microphonic. They certainly test in a varied and lively fashion and it's common to find sections widely different. A bit of a Marmite valve with some folks but they seem accepted these days.

Here's a good thread about similar on Audiogon,
https://forum.audiogon.com/discussio...mperex-pq-7308

Adrian also asks about the 5751 in Phono II. I used them in mine and felt 5751 were deeper sounding and less bright than some ECC83. Mullard ECC83 are excellent. The brightest/liveliest ECC83 I used in any gear were EI flat plates which were said to be be Telefunken copies.

Another tweak is to try the first stage with and without the cathode bypass capacitor. It makes a small change to gain and sound

[colin.hepburn]

Hi All
If it’s any help for Adrian
I Use the Russian 6N1P-EV in my CF pre and find then nicely dark and balanced and don’t want to change them anytime soon but as we all hear differently others may differ but don’t let the cheap price put you of at least trying them the link is where I got them

http://tubes-store.com/product_info....roducts_id=832
PS in my phono II. i have 5751 and two JJ83s and works very well for me