E288C Valve

[Spectral Morn]

I was planning on doing some tube rolling in my EAR 864 pre-amplifier, and I was checking to see what Ecc82 and 83 tubes I had. And I found these two white boxes with a valve I know nothing about in them....so I did a bit of looking .....

and found that I have a pair of very rare German valves. These are Siemens 6dj8 types and are called e288c basically about as good an ecc88/6dj8 valve as you can get (also big money to buy). I will post pictures tomorrow (done tonight) and I will have to test them to see if they are okay. These came out of a box of valves my dad had when he used ham radio gear with valves in them.

According to what I have read these may be amazing....Any one got an opinion or experience of these. Can you put them into an amp that uses ecc88/6dj8/6922 tubes....without a problem.






Regards D S D L

[Spectral Morn]

Spent a few hours this afternoon testing signal and some power valves, with my Mighty Mite TC162 tube tester...YIPEEEE it works.



Most of the signal tubes ECC83 and ECC88 measured fine (even a white and yellow label Mullard ECC83 were okay ) one ECC82 was just about okay floating above the middle Question mark Zone.

However 2 EL34's were good on Shorts, Emissions and Grid leakage but had falling levels on the Life test....they dropped fairly quickly into the questionable zone....are these stuffed ? The manual with the tester says bin them....


Regards D S D L

[The Grand Wazoo]

Neil,
I'm not 100% sure but I think I may also have some of these. I can't check them though till the weekend. I do know I have some pretty obscure ECC88/6DJ8/6922 types I've bought in the past as 'what if?' speculatory purchases.

I've been meaning to try them out in my SP8 for ages, but it sounds so good at the moment, I don't want to rip it apart!

[Spectral Morn]

Neil,
I'm not 100% sure but I think I may also have some of these. I can't check them though till the weekend. I do know I have some pretty obscure ECC88/6DJ8/6922 types I've bought in the past as 'what if?' speculatory purchases.

I've been meaning to try them out in my SP8 for ages, but it sounds so good at the moment, I don't want to rip it apart!

If you do, they (E288C) are selling in the USA for $300 +. They may be more common here in Europe, but maybe not ? I want to know a bit more before I put them into anything, but from what I have read they appear to be gold dust.

I want to test them too and sadly I have no settings info accept for ECC88,6922,6DJ8's maybe the e288c is the same ? I just don't know


Regards D S D L

[Mike]

I want to test them too and sadly I have no settings info accept for ECC88,6922,6DJ8's maybe the e288c is the same ? I just don't know

Specs HERE and HERE

[Spectral Morn]

Thanks Mike but I haven't a clue what that is all about ....I be a bit stupid about such things. The Mighty Mite allows you to set up via an idiots guide (instruction book tells you what to do) so you select any pins needing to be switched out(isolated), filament voltage the load ( selects applied voltage and load resistance, so valve can be tested to its rated current), I also need to know the control grid pin so I can test emission and grid leakage...I need to know those to run a test.

I have a choice of 10 pins for settings A and D see photo close up...here http://theartofsound.net/forum/showthread.php?t=2007.


Can you interpret this for me MIKE....please. What might be the same as an ECC88 (specs)etc I can use settings suggested (in the book) if similar.....

I have got one spec from this pdf, i.e the cathode current which seems to be 40ma, so i know the load now....I still can't figure out the rest.


Regards D S D L

[Barry]

I have a pair of very rare German valves. These are Siemens 6dj8 types and are called e288c basically about as good an ecc88/6dj8 valve as you can get (also big money to buy). ... According to what I have read these may be amazing....Any one got an opinion or experience of these. Can you put them into an amp that uses ecc88/6dj8/6922 tubes....without a problem.

Regards D S D L

Hi Neil,

Put simply the E288CC has no direct equivalents. It is similar to, but not identical to the E88CC and its variants (6DJ8, 6922, ECC88 etc.). The E288CC has lower gain, higher inter-electrode capacitance and heater current than the E88CC. Since the E288CC has higher absolute limits than the E88CC, you could at least try them in your amp without damage. How they sound that can of course only be found by trying them.

If you are looking for the 'Chateau d'Yquem' of E88CC 'bottles', then you need the 1950s Siemens & Halske CCa, the 1960s Telefunken CCa, or early 1960s Lorentz CCa valves (in decreasing order of desirability). A pair of Siemens CCa went on eBay three weeks ago for £98. I was thinking of bidding for them. Wish I had, they were a bargain, but I have no idea of their provenace; the description just said NOS.

Regards

Barry

[Spectral Morn]

Hi Barry


Thanks for the info....I would like to test them before trying them. I know my Dad won't remember much about them...if he stopped using them because they had gone off.

Can you interpret the specs at the end of Mike's links ?

The other tubes you list are very expensive in the states £98 looks cheap to me compared to what I read last night. Its like Antiques this end of the audio game.

Regards D S D L

[Barry]

The Mighty Mite allows you to set up via an idiots guide (instruction book tells you what to do) so you select any pins needing to be switched out(isolated), filament voltage the load ( selects applied voltage and load resistance, so valve can be tested to its rated current), I also need to know the control grid pin so I can test emission and grid leakage...I need to know those to run a test. .....


I have got one spec from this pdf, i.e the cathode current which seems to be 40ma, so i know the load now....I still can't figure out the rest.

Regards D S D L

Neil,

I would suggest setting the anode (pins 1 and 6) voltage to 100V, anode current will then be 30mA. Amplification factor 25. Grid pins are 2 and 7 respectively.

For an anode voltage of 60V, the anode current should be 15mA (not 1.5mA as quoted in the first data sheet).

See how you get on with these settings.

Regards

Barry

[Spectral Morn]

THanks Barry

2 and 7 are the same for the ecc88/ecc83 and 30/40 ma is a setting...excellent we are getting some where.

Is annode the same as filament ? I need the filament voltage.


Let you know how it works....


Regards D S D L