[baileyler]

12 Vintage Amperex and Mullard 6DJ8 ECC88 Vacuum Tubes Tested - $250 $225 shipped (in USA)

While I have these priced as a group, I am open to splitting them up for the right offer.  I am also open to trade offers.

All of these tubes are either Amperex made or Mullard made, although they may be branded otherwise.  Details are provided below.

I am selling a majority of these for a third party, but I did include a few tubes of my own that fit into this group.

Too many people play the “NOS” game, and I will never call something NOS unless (1) I have the original box (or I know for a fact that tubes were pulled from a bulk pack), (2) the tubes actually look unused as evidenced by the printing and pins (or there is a legitimate excuse for their appearance, such as the tube was stored under damp conditions), and (3) the tubes actually test like new.  In the real world, that eliminates the vast (vast) majority of vintage tubes out there from NOS classification.

A small handful of the tubes might be NOS but, for the purposes of this ad, CONSIDER EVERYTHING USED. 

All of these were tested on my Weston 981 III, which I find to be very reliable for transconductance measurements on small signal tubes.  Min (65%) value is 1350, making about 2000 “theoretical” 100% (Gm = 6X meter).  The results are as follows (“RT” = right triangle) (sorry for my poor formatting):

# /   Manufacturer /   Brand /   Date Code /   Test /   Notes

1   Mullard   Dario Miniwatt   B0B2      2350/2350   Medium halo getter, 1970
                  
2   Mullard   Rogers   B8L1      2250/1850   Large thicker halo getter, 1968
                  
3   Mullard   IEC Mullard   B4L3      2600/2550   Large thinner halo getter, 1964

4   Mullard   Mullard   B3C3      2500/2150   Large thinner halo getter, 1963
                  
5   Mullard   Amperex   ?      2300/2100   A-frame dimple getter, mid-1960s

6   Mullard   Amperex   B6J1      2450/2600   A-frame dimple getter, Tektronix label, 1966

7   Mullard   Amperex   B7A4      1500/1450   A-frame dimple getter, 1967
                  
8   Amperex   Mullard   RT2G1 (?)      2100/1800   A-frame dimple getter, 1962

9   Amperex   Hewlett Packard   RT2L2   64-16   2000/2000   A-frame dimple getter, 1962

10   Amperex   Mullard   RT2L?      2350/1900   A-frame dimple getter, 1962

11   Amperex   Mullard   RT0L3      2400/2350   A-frame dimple getter, 1960
                  
12   Amperex   Amperex   RT8K2      2200/1550   Small halo getter, 1968

For reference, a new 6DJ8 tests typically (on average) tests in the area of 2100-2300 on this Weston 981 III.

All tubes were clean for shorts and leakage.

I went to the added step of testing these on a Kaye Small Signal Tube Checker.  For those not familiar with the Kaye Small Signal Tube Checker, this device was sold some time back by Kaye Audio, and provides an INDICATION (see my TERMS AND CONDITIONS below) of noise, microphonics, gain and distortion.  I do not use this piece of equipment very often, but it does provide what I believe to be useful information.  Just as a note, it appears that Triode #1 on the Kaye corresponds to Triode #2 on the Weston, and vice versa.

The noise and microphonics tests are totally subjective as they involve actually listening (the unit has a built in speaker as well as a headphone jack), and I do not have a lot of experience judging, but here is my view.  Scale is 0-5, with 0 being worst and 5 being best (noise/microphonics):

               Noise (T1/T2)   Microphonics (T1/T2)
Tube #1   5/5      4/5

Tube #2   3/5      5/4

Tube #3   5/5      5/5

Tube #4   5/5      5/5

Tube #5   5/3      5/3

Tube #6   5/2      5/3

Tube #7   2/3      3/3

Tube #8   5/3      5/5

Tube #9   5/5      5/4

Tube #10   5/5      5/5

Tube #11   5/5      5/5

Tube #12   4/5      5/5

The gain test is supposed to measure the gain of a tube in a class A circuit, cathode bypassed, with a -10 db 500 hz tone applied to the grid (please do not ask me what this signifies), and involves reading a meter (spec for 6DJ8 is said to 27db under these test conditions).   The results are as follows:

Tube #1   27/27

Tube #2   27/26

Tube #3   26/26

Tube #4   27.5/27

Tube #5   28/29

Tube #6   26.5/29

Tube #7   29/30

Tube #8   27.5/28

Tube #9   27.5/27.5

Tube #10   27/28

Tube #11   28/28

Tube #12   28/27.5

The output/distortion test is supposed to show the maximum output a tube can produce (measured in Volts, with spec being around 50) at 10% distortion.  I do not, however, know how this might translate to sound.  All tubes were right around the 50 V mark on all triodes (some may have been slightly higher or lower).

Based on these results, I would estimate that a typical tube pro would probably sell Tubes #1, 3, 4, 9, 10, 11 and 12 as phono grade (very low noise/microphonics); Tubes # 2, 5 and 8 as line grade (low noise/microphonics); and Tubes # 6 and 7 as a standard driver grade.

Also, based on test results these should all generally be considered singles. 

I can provide additional information or pictures upon request.

GENERAL TERMS AND CONDITIONS – PLEASE READ CAREFULLY

Please note that these tubes are being sold 'AS IS', but I will guarantee against a material misdescription in the listing.  In such event, I will refund purchase price less shipping upon return of the tubes in the same condition as sent.

PLEASE NOTE THAT I CANNOT GUARANTEE (OR EVEN REMOTELY PREDICT) HOW THESE TUBES WILL SOUND OR PERFORM IN YOUR EQUIPMENT.  THE TEST RESULTS ARE ONLY PROVIDED AS AN INDICATION OF TUBE PERFORMANCE IN A VERY LIMITED (AND NON-IDEAL) ENVIRONMENT.  OTHER THAN AS SET FORTH ABOVE, I EXPRESSLY DISCLAIM ANY LIABILITY WITH RESPECT TO THESE TUBES OR RESPONSIBILITY FOR YOUR USE OF THEM.

Money order/cashiers check/personal check preferred, but all (other than US Postal money orders) must clear my bank first.  I also accept Paypal for convenience (but add 3% to the total for USA, and 4% to the total everywhere else).

Trade value might be considered, particularly for vintage EL34/6CA7 and 6550 tubes.  In any event, feel free to propose something (tubes or audio equipment) and I will at least consider it and respond.

Shipping in the USA via US Postal Priority Mail is included.  If you are outside the USA, contact me for a shipping quote.

Please check my feedback on Audiogon, Videogon and Ebay (ID=baileyler) and buy with confidence.

[baileyler]

Price reduced to $225 shipped (in the USA).

Of course, still willing to split and listen to trade possibilities.

See my other listing for 59 6SN7GTBs as well.

Tough to beat the price for either group.  Will discount a tiny bit further if taking both groups.

[Big Red Machine]

Just tried and resold the Amperex orange globes as they were very muddy in my preamp (but dead quiet).

Returned for refund a quad of Mullard 6DJ8 ECC88's from Ebay because they were so noisy just this morning.  They sounded great and had wicked strong bass but the noise was audible above the music.

Do you think there is a quad of strictly Mullards buried in this heap that would mate well together in a preamp?  it appears as if you have listened to these to see if they have audible noise.

[baileyler]

I don't think by any measure I can make a "matched" quad (pairs may even be stretching it a bit on this group), and certainly not of the same internal construction.

I haven't actually listened to any of these tubes other than through the test equipment (Kaye).  Based on feedback from other tubes I have sold, I have found the Kaye to be fairly rigorous for noise and microphonics (at least for audio equipment).

Are all four of your tube positions eqaully critical for sound?  My preamp uses 3 6922/6DJ8, and one of those is significantly more important than the other two.  If you like one or more qualities of a particular tube, you may want to try rotating the order to see if that makes a difference.

[baileyler]

I'll try another bump.

[baileyler]

Any interest (along with my other posts)?

Of course, still interested in trades as well.