Fair question to ask Archie, to qualify my situation. Like 9 pin input tubes and inverter's....in which, you know I roll like changing my socks... = a lot.....and always require that slight tilt and roll to pull in and out....never straight in or out and the same for the output tube sockets. The quality of Steve's socket choice is to be commended = Quality.

These two Quads in question, just plain flat out get stuck....and let you know you are DONE....and do not force.

Scratch my head disbelief?

While not ideal, do you get enough purchase for good electrical connection?

Do they go far enough in to connect....are you asking?
Of course, without fitting flush down in ~ I would never turn my ZMA on.

Define....."enough purchase".....I have these on loan from JD.

I had em in a Torii III. I used the RFT for a couple hundred hours as well.

JD

Stone,

If only you had some calipers ...

I measured several tubes' pin diameters:

Raytheon 12AU7:  0.040"
Raytheon 12AX7:  0.040"
New Mullard 12AX7:  0.039"
Steve's Russian ZMA power tubes:  0.040"

Tung-Sol EL34B:  0.093"+
Tung-Sol KT66:  0.093"
Gold Lion KT66: 0.093"
Russian 6Ps:  0.093"

So, good consistency across tubes and brands.  If your tubes are big pinned it would be unusual but that's the only thing that makes sense.

So, bottom line:

Tubes are slightly larger in diameter/pins

~ or ~

these particular ZMA tube sockets are slightly out of spec.....that are accommodating the tubes that ship with them/KT66, 7 pin and of course fit my subsequent KT66 Tung-Sol current production tube purchases/two other quads.  Plus, luck on the Reflector 6 pin quad 6PS3-E's....fitting.

Once again, I have ruled out operator error/ME. These two quads will not fit in my ZMA sockets:
RFT German EL34's/8 pin
&
PSVANE 5881/6 pin.

Hard to say if tube pins or sockets.  My guess is sockets.  My RFT EL-34's slide in and seat with no problem.  Now, I am not sure the history of my "red capped" ZMA, which is the same run as Stone's, as I am the second owner.  It could be that the first owner did the deed and applied whatever pressure was necessary to get the sockets "opened up" enough to handle any tube.  But then there is Archie's post showing some rather impressive tube pin diameter consistency amongst various tube types.  Sooooo then what???

Man, this is a head scratcher for sure.  Time for a direct message to Steve as he may shed some light.  It would be a shame not to run whatever compatible tube you want Stone, but I don't blame you for backing off.  It simply is not worth the tube or socket damage at this point.

Yeah, none of it makes any sense.  I don't believe the sockets used in ZMA and Torii are different.  So why did those tubes work fine in NormD's amp?  

Sorry, my bad.  I meant to write "JD", not NormD.  He has a Torii and these tubes were not issue in his amp.  I am assuming the sockets are the same make/model, but I could be wrong.

Thanks for that Steve.  Very helpful/useful to know.

Stone, time to greez 'em up!  May the Force be with you.

Thanks JD....I was going to ask you just that.

Thanks again Steve, now, inspecting the two quads in question....with an LED Flashlight and my geek magnified glasses (also visible to the naked eye when you look close and feel too-blobs on the tips of the 5881's for example)....some filing is in order and minimizing stress to my output sockets.

I will get to it later in the week and get back. This morning, I'm enjoying my Ediswan, Telefunken & 6PS3-E Reflector quad...... .

Filing, wiping clean and then wiping on/applying XLO TPC.

https://www.kosmasaudiovideo.gr/showprod.php?id=1961

TPC goes way back to over a decade ago....one of my favorties....and glad I still have a few sealed packs. Time to break it out again.

".....chemically-treated wipe neutralizes oxidation, protects against corrosion, and even - by soaking into and filing micropores
in plated contact surfaces - increases total effective contact area, for better signal transfer and reduced low-level information loss."

I received my RFT ( SIEMENS ) - NOS - EL 34 from someone in Germany.  I had to problem inserting them into my ZMA sockets.  The sound very good and are giving my 6P3S's a good challenge but the latter seems to be the winner in overall dynamic range and air.  I'll leave the EL34's in for a week and see how they settle out.

My PSvane EL-34PH's smoked the Tung Sols in an A/B.  I haven't put the RFT's in yet to compare, but hope to do so within the next week or two.

Quote:


Right??  It is quite remarkable!

Jeff:

So if you had to do it all over, would you pick the PSvane EL-34PH's or the 6P3S's?

Why do I have this feeling you will tell me you want both...

Norm

6P’s for price, first and foremost.  And the beautiful mids.  However, there are things the PSv’s do better and I really enjoy having them in.  But considering the price difference....  Ive gotta go with the 6P’s.

They are so rock solid in their Bias & Balance and their even handed rise on the Meter's. Archie, it will be interesting to see what kind of life these are capable of, for sure.

I popped my set back in last week after a long stint with my PSvane EL-34PH's.  Yep Stone, they rise evenly and got settled quick.  Had them re-biased in a matter of seconds.  And after checking a few times throughout the night, they were still sitting put where I left them.  Pretty incredible.  

I just get a feeling these are some pretty solid, and robust tubes.  Not based on anything scientific, just a gut feeling.  For our sake, I hope I am right!

Cool Archie, great price too.
Norm, I second that motion....sound comparison.

I ordered four last night  :)

It will be an interesting comparison.

Looking forward to your impressions.  Hopefully yet another tube that performs inversely to price.  

My thoughts exactly. I ordered both myself yesterday. Those are new in boxes?

I found my best combo's so far:

Ediswan's or Mullard's as inputs ...with, always the painfully expensive but worth it Telefunken's as inverter's and new stock KT66 Tung-Sol's. .....NOS RCA 0A3's.


My other combination is:

Mullard's ONLY as inputs ...with, always the painfully expensive but worth it Telefunken's as inverter's and Cryo 6P3S-E's. .....NOS RCA 0A3's.


Running straight from ZDSD output trannies.....attenuating input gain with ZMA. Pure and simple/puts me the closest to the Music and the differentiation of Tubes is/are all there.

I keep the original 6N23P's around as a harken back to their Sig....but they ain't my Gig, compared to the above compliments.

The two pair of Tungsrams are going to Audiogon and I'm staying pure with/from my source ZDSD and selling my ARC Line Stage too.



~ All NOS Platinum graded Tubes from Upscale Audio (except 6N23P's):

(Great Britain) Mullard 7308/E188CC ~  2 pair (both pair Cryogenic)
(Germany) Telefunken 6922/E88CC ~ 1 pair (painfully expensive/worth it)
(US/Great Britain) Ediswan CV2492/6922 ~ 2 pair (one pair Cryogenic)
(Hungary) Tungsram 6922/E88CC ~ 1 pair
(Hungary) Tungsram PCC88/7DJ8 ~ 1 pair

(Russia) 6N23P's ~ 2 pair/came with ZMA.  








Listening Room:



Room Treatments from Michael Green & my Home Brew


Sony as Transport (DVP-NS57P)
Illuminati D-60 Digital Coax IC ~.5 meter


Shunyata Research Zitron Alpha Digital Power Cord to ZDSD {Significant}


Decware ZDSD DAC / Recorder
***************************************************************
W/Steve's Output Transformer's/kicking to the Curb quite a few superb DAC'S
***************************************************************
(@ -20 Ref Level, 0.0 Input volume and @ 16/192)



WBT-0102Ag RCA Kimber Select KS1030 ~.75 meter


Decware Zen Mystery Amplifier
~BIASED at *56* mA~
NOS/Platinum/Mullard E188CC/7308's in my A12 an B12 Input positions Cryogenic~NOS/Platinum/Telefunken 6922/E88CC for Inverter Tubes~NOS RCA 0A3's & matched Quad/Tung-Sol KT66's or 6P3S-E's




***************************************************
Kimber Select KS6063 Speaker Cable 8ft WBT-0681-Ag Spades
***************************************************



Acoustic Zen Adagio - Black Pearl (Modified)
.....enjoying from 8 ohm ZMA Taps


Caintuck Audio Eminence Alpha 15" OB BASS Unit
at 43Hz, with my Velodyne CHT 130 watt plate amp and 0 degree phase.....at 1/8th volume on plate
Plate Amp....regen'd clean ~ plugged into P3
Auralex Subdude (a must)
(NOTE: Only needed when the recording calls for...Open Baffle Bass has been the best integration I have witnessed when needed and called on)







Acoustic Zen Adagio's x-over's Modified/Full Range with Mundorf MCap Supremes-single Cap to each Tweeter/4.5k cross
(Gutted: 3kHz/18dB/Octave, Linkwitz/Riley Crossovers....with all crappy parts = gone)


ZMA, updated with robust Western Electric Bias/Balance Meter's and new Resistor's ~ Feb/17

XLO Pro Power Cord to ZMA
Shunyata Research Zitron Alpha Digital Power Cord to ZDSD {Significant}
PS Audio P3 Power Plant / Pangea AC-9SE from wall to P3
(Transport and ZDSD, Regenerated/*120*~ Multiwave off...ZMA on High Current Output)
System configured on Floor ~ Townshend Audio CD Seismic Sink deployed & other Isolation devices.