|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
68.48.234.148
I have recently purchased 4 used Sophie 6SN7 Tubes Grade A. I have received 2 of them. Ralph says to put one in the back row in the middle.
When I get the 2nd set (hopefully next week). Ralph says then to place them again in the back row but flanking the middle tube.
Note: There is not enough space to use all Sophie tubes in the back row due to there larger girth.
Have any of you used the Sophie tubes on the M-60's? And if so, did you use just one tube or did you use 2 tubes in each amp?
Thanks,
Ken
Follow Ups:
Why do you Sophia chinese made tubes when you can get US made tubes?
Sound Quality.
I have found that the "Full Music" branded tubes are the same visually and sonically with the higher cost Sophia tubes.
I'm really happy with the 6 Sophia tubes in my M-60's. I'm not sure how many hours these tubes will last. Any idea anyone?
I was thinking of buying some spares, but they are expensive.
I found some Shuguang 6SN7-T CV181 tubes with brass bases that look very similar to the Sophie tubes and are a little cheaper. However, they have to be ordered from China.
Questions:
Is perhaps the Shuguang the OEM for the Sophia tubes?
Has anyone tried these tubes?
So far no-one has reported any longevity issues.
The operation of the 6SN7s in the voltage amplifier section is pretty conservative and we've seem some 6SN7s go 50,000 hours!
In any event, I've never tried the Sophias.
In the Mk. 3.3, the frontend tubes are arranged in a 'T'...
The front single is the cathode follower, the left and right rears are the input-gain tubes running in parallel, and the rear center is the Voltage-gain section that I can never remember the functional name of. I've replaced my Voltage-gain single with an A-S plug to reduce the amp's gain. (Ralph used an 'N7 as a current source in the earlier versions but replaced that tube with a solid-state current source in the 3.3.)
I'm using Tung-Sol roundplate 6SN7GTs in my six positions. None is electrically 'matched' to any other, and none tests particularly well, but WOW do they ever sound good. :-)
----------
Tin-eared audiofool, large-scale-Classical music lover, and damned-amateur fotografer.
William Bruce Cameron: "...not everything that can be counted counts, and not everything that counts can be counted."
I don't own an M60, but just from the 2 photos and from what Jeff said, I would guess that the middle rear tube of 3 is a CCS (Constant Current Source), solid state in a 3-tube 3.3 and tube-based in the 4-tube 3.1 version. The CCS does not have much effect on sonics per se, but the implementation can have an effect, which is to say that there is no need to use a boutique 6SN7 as a CCS. Two of the remaining three tubes, in a 4-tube input/driver stage, must therefore be in the dual-differential cascode topology. That's what does the work of voltage gain that drives the whole amplifier. Essentially, that's what you are hearing; the output tubes add little to no gain; they serve mainly to convert voltage to current. The remaining tube is a cathode follower, one half of each twin triode drives one half of the total of 8 output tubes. The CF takes the output from the cascode and reduces the net output impedance of the signal from the cascode so as to drive the output tubes. Both the dual-differential cascode AND the Cathode follower benefit from a CCS, so I don't know which one has a solid state CCS or if both do in the 3.3 version.
We phased out the 6SN7 CCS circuit with the Mk3.2. The new solid state CCS has an order of magnitude greater performance.
So the outside tubes are the bottom of the cascode, the middle rear is the top of the cascode and the front tube is the CF driver.
Thank you so much for the information.
So, here is what I am gathering for the M-60' Mk 3.3 version;The best tubes should go at the 2 rear left and right positions. The rear middle position is not affected as much by the tube quality and therefore there is not much need to use (boutique Sophie)tubes in that position. Actually the Sophie's are wider and it would be impossible to fit 3 of them across the back row.
And the front center tube should be a 6SN7GTB per Ralph at Atma-sphere.Does that sound like I got it?
Edits: 03/26/17
You'd be much better off with facts from Ralph re what tube does what than conjecture from me. But the concepts are correct. I find it difficult to understand how the two outside tubes among the rear 3 (the tube on the far L and the tube on the far R) are together to form the dual-differential cascode, because those tubes are interconnected in a rather complex way, and I doubt that Atma would have them separated by the presence of the middle tube. It certainly could be the case, but I don't know for sure. That's why I suggest you ask Ralph.
By the way, what is a "Sophie" tube, and in what way are its dimensions different from a 6SN7GT, GTA, or GTB?
...to the Sophia 6SN7.
----------
Tin-eared audiofool, large-scale-Classical music lover, and damned-amateur fotografer.
William Bruce Cameron: "...not everything that can be counted counts, and not everything that counts can be counted."
Took that quote from the Sophia website. It's an odd one, because CV32/33 and CV181 are in fact NOT 6SN7s in any way. I have seen CV181s, and they generally resemble those Sophia tubes being sold as 6SN7 replacements. They are electrically different from a 6SN7, and that's why they will sound different from a 6SN7 if plugged into a circuit designed for a 6SN7. On the other hand, CV1988 is a legitimate alternative name for a 6SN7. I have some Mullard/Brimar tubes that are labeled "6SN7GT/CV1988". I have no idea what Sophia is smoking.
Thanks,
The Sophie tube is an Audiophile tube that is taller and wider than the normal size 6SN7 tubes.
nt
Thanks, I have the M60's Mk3.3.
Do you know the tube numerical order?
Example; I have been reading that tubes placed in position 1 or 3 do ...
I just can't figure out the tubes numbers. I sent Ralph a email also.
The two outer tubes, left and right of the top of the 'T', are V1a and V1b. The center tube of the top of the 'T' is V2, the top (Voltage-gain-portion) of the cascade. In the M60 3.3, there is no V3; in former versions this was the CCS.
So if you LOVE the sounds of the Sophias (NOT 'sophies'), use your four in the four V1 positions; I'm stickin' with my TSRPs. :-) :-) :-)
Hope this helps.
----------
Tin-eared audiofool, large-scale-Classical music lover, and damned-amateur fotografer.
William Bruce Cameron: "...not everything that can be counted counts, and not everything that counts can be counted."
Jeffreybehr, hey bud I am still waiting for an invitation for listening session :) and no i don't wish to join phonix audio society :))
Lawrence
Thanks for correcting me on the name of the Sophia tubes.
If I get 2 more tubes is there any more sonic improvement to be gained if I place them in the middle back (V2)?
Since the Sophia tubes are larger and wider I would need to use perhaps a tube socket saver to lift the center tube.
Well I did manage to place 3 of the Sophia 6SN7 tubes across the back row in the M-60's. In order to get the center Sophia installed I used a tube socket saver suggested by Ralph and available on Amazon.
I must say that the sound quality has gone up a couple of notches, very nice improvement.
I'm really happy with the 6 Sophia tubes in my M-60's. I'm not sure how many hours these tubes will last. Any idea anyone?
I was thinking of buying some spares, but they are expensive.
I found some Shuguang 6SN7-T CV181 tubes with brass bases that look very similar to the Sophie tubes and are a little cheaper. However, they have to be ordered from China.
Questions:
Is perhaps the Shuguang the OEM for the Sophia tubes?
Has anyone tried these tubes?
...use any kind of socket extenders, just find a pair of standard-size RCA or Ken-Rad VT-231s (or TSRPs!) for that position.Where (rotationally) are you running your preamp's volume control? If it's sort of low and you're 'throwing away' 10 or 20dB of the preamp's Voltage gain, do as I did and buy a pair of Ralph's tube-replacement plugs and replace Vs3 and turn your volume control up 10dB.
----------
Tin-eared audiofool, large-scale-Classical music lover, and damned-amateur fotografer.
William Bruce Cameron: "...not everything that can be counted counts, and not everything that counts can be counted."
Edits: 12/08/17
With the socket saver there will be enough room to place 3 of the Sophia's across the back row in the M-60's.
I do have many 1950's era RCA's and they do sound good. But, I think the Sophia's add a little more air, dynamics, and increase the soundstage.
I don't know what is inside that CV181-like glass envelope that Sophia uses. If it's a 6SN7 internally, then using them is fine. On the other hand, if it's truly built to CV181 specifications, then keep in mind that the filaments draw 0.95A. That's 50% more current than a 6SN7 filament. If you use 3 or 4 of the Sophia tubes in an M60, it might be stressing the filament supply. Probably using one or two is OK. This issue would be in addition to any issue arising from alteration of the operating points of the tube itself, if it's a CV181.
FAQ |
Post a Message! |
Forgot Password? |
|
||||||||||||||
|
This post is made possible by the generous support of people like you and our sponsors: