Question - ECC88 and other related valve

[montesquieu]

Just pondering what valves to put in my Radford STA100 (just to while away the time).

I already have plans to try a quad of the new Sophia KT88-ST tubes. I'm a KT88 fan from way back ... I'm hoping Will will set up the amp to take KT120s should I want to check those out in it, but first of all I want to use it with the valves it was designed for. The Sophias are expensive but not so expensive as GECs.

Input valve is an ECC88, followed (rather unusually, possibly uniquely) with a pair of EF184 pentodes, which provide the splitter function.

I have a supply of pristine, NOS EF184 Mullards, thanks to Valvebloke's eagle eyes who sent me in their direction.

However the ECC88 is a puzzle - I'm a bit confused about what I can use in there. For example I've had great results in the past with assorted JAN 6922s (both Phillips and Sylvania) - but I dont know if they can be used as ECC88s despite what some ebay sellers have in their listings. Also there's the 6DJ8 which I think is just another name for the ECC88 - or is it?

Can anyone enlighten me here? And possibly suggest some sensible choices for this position.

I've never really been one for exotic, fragile of 'NOS' valves after a few bad experiences years ago where stuff went 'phut' at great expense within weeks or even days. So new production even if expensive could be sensible, otherwise decent sounding but bulletproof is the priority. I only need two.

Sophia KT88 looks cool but of course won't be visible in the Radford:

http://www.sophiaelectric.com/images/se/KT88_blue_glass.jpg

[Firebottle]

The ECC88 is a far better valve than the 6922, it is a lot more linear.
The 6DJ8 is an equivalent.

Go for Telefunken valves, they really are good. If you can get Will to make the Radford accommodate the PCC88, which has a different heater voltage, you can get NOS Tesla for around £6 each.

:)

[farflungstar]

Can't comment on the smaller tubes Tom, but I'd definitely recommend trying kt120s - specifically designed for audio and in my opinion superior to 300b/845/88 which I've lived with. Of course it's subjective but they are dynamic in a way I haven't heard before with other tubes.

[montesquieu]

Can't comment on the smaller tubes Tom, but I'd definitely recommend trying kt120s - specifically designed for audio and in my opinion superior to 300b/845/88 which I've lived with. Of course it's subjective but they are dynamic in a way I haven't heard before with other tubes.

I know, I have some experience of KT120s, heard quite a few KT120 amps including the Leben 1000p which was very good indeed, had it driving the Tannoys for quite a few weeks ... but it all depends on the implementation. I also owned a KT120 PP recently which was perfectly decent, but was effectively blown away by 25w of Radford EL34 STA25, something I would never have expected. This was an amp specifically designed for KT120s. It's far from automatic they'll sound any better than KT88s.

I want to start off with the Radford running good quality KT88s. Later, I can experiment.

[montesquieu]

Go for Telefunken valves, they really are good. If you can get Will to make the Radford accommodate the PCC88, which has a different heater voltage, you can get NOS Tesla for around £6 each.

:)

Hmm I actually have a set of five Telefunken PCC88s (NOS when fitted not long before I bought the amp) that I removed from my EAR 912 when I got it ... it was sounding different to when Petrat came to demonstrate his, and it was Peter's sound that I preferred. So I replaced them with factory PCC88s from EAR and preferred that. I had been planning to sell them on. Not sure I'd mod the amp though. I know the Telefunkens can be very expensive I recall having a pair at some point or maybe that was ECC83s?

[Jazid]

Hmm I actually have a set of five Telefunken PCC88s (NOS when fitted not long before I bought the amp) that I removed from my EAR 912 when I got it ... it was sounding different to when Petrat came to demonstrate his, and it was Peter's sound that I preferred. So I replaced them with factory PCC88s from EAR and preferred that. I had been planning to sell them on. Not sure I'd mod the amp though. I know the Telefunkens can be very expensive I recall having a pair at some point or maybe that was ECC83s?That would be either... If you want a guaranteed pair of gold pin NOS E88CC frame grids then drop me a line.

Sent from my GT-I9195 using Tapatalk

[Batty]

PCC88s, are they 7v heaters?

[montesquieu]

PCC88s, are they 7v heaters?

yes compared to 6.3v for ECC88. I assume that means you can generally use ECC88 in a PCC88 application, but not the other way round without modification.

[Batty]

I would have thought 7V across the ECC88 heaters would be a no no as it is too high.

[forsell]

yes compared to 6.3v for ECC88. I assume that means you can generally use ECC88 in a PCC88 application, but not the other way round without modification.

The other way round: PCC88 in ECC88 application. However filament voltage should be no lower than 6,3 V. This is not always the case when you MEASURE the real voltage across the pins of heater in real world amps. Some amp manufacturer do not follow the prescribed 6,3 V. According to valve manufacturer specifications allowable tolerances was +/-10% hence with a PCC88 running on 6,3 V heater voltage you are just "on the edge" but it is still OK.

ECC88 breed:

1) Standard quality

ECC88 = 6DJ8 = CV5358 = M3624 = 6Н23П

1st: European valve code
2nd: American valve code
3rd: British code (special applications valve), "CV" stands for "Common valve"
4th: British code (special applications valve)
5th: Russian code

2) Same specifications, higher quality for special applications (military, public services, telecommunication etc) Longevity min. 10 000 hrs

E88CC = CV2492 = Cca = 6922

3) Same specifications, 7V filament voltage

PCC88 = 7DJ8

1) and 2) fully interchangeable as they only differ in quality. 3) interchangeable with limitations as specified first.

[ovlov854]

I came across pair of NOS E88CC Tesla with gold pin and marked with Crossed Swords and red tips.
One I put into my SW1X DAC 1 and the other into my RWA Valve HPA
The improvement was astounding

[ovlov854]

Rummaging around in my valve box I have come across a pair of Mullard ECC88
I remember using these in an X-Box HPA
They are supposed to be a close pair and certainly produced much improved results
I do not have access to a tester so I do not know how much life they have.

Tom........... Yours to try for postage if you want

[WESTLOWER]

I came across pair of NOS E88CC Tesla with gold pin and marked with Crossed Swords and red tips.
One I put into my SW1X DAC 1 and the other into my RWA Valve HPA
The improvement was astounding

Hi Martin
so I can improve my DAC also with these tubes?
thoughts?

[ovlov854]

Hi Martin
so I can improve my DAC also with these tubes?
thoughts?

Hi Adam .....Yes I reckon so. First my SW1X was changed to the lower output setting by Slawa and I did find his Russian tube a little coarse.
I swapped to a gold pin Brimar E88CC and found that much more to my taste
Then the Teslas came my way and I thought I would take a chance as they were a matched pair and would be saleable if I did not like them.
Much more detail and ambience so they were a good buy.

[montesquieu]

Hi Adam .....Yes I reckon so. First my SW1X was changed to the lower output setting by Slawa and I did find his Russian tube a little coarse.
I swapped to a gold pin Brimar E88CC and found that much more to my taste
Then the Teslas came my way and I thought I would take a chance as they were a matched pair and would be saleable if I did not like them.
Much more detail and ambience so they were a good buy.

Hi Martin - thanks hugely for the offer but my Radford won't be ready for a month or two yet, so I won't have anything to try the valves out in until the New Year - happy if you extend to loan to Adam instead.

All this valve talk is really displacement activity on my part while it waits its turn on Will's bench.

[WESTLOWER]

Hi Martin - thanks hugely for the offer but my Radford won't be ready for a month or two yet, so I won't have anything to try the valves out in until the New Year - happy if you extend to loan to Adam instead.

All this valve talk is really displacement activity on my part while it waits its turn on Will's bench.

:thumbsup:

[ovlov854]

:thumbsup:

happy if you extend to loan to Adam instead.
Hi Adam yes indeed pm me with your address and you can try them by all means.
However be aware they are used and you should try to get them tested just to make sure

[IslandPink]

http://tdsl.duncanamps.com/tubesearch.php

[SW1X]

Hi Adam .....Yes I reckon so. First my SW1X was changed to the lower output setting by Slawa and I did find his Russian tube a little coarse.
I swapped to a gold pin Brimar E88CC and found that much more to my taste
Then the Teslas came my way and I thought I would take a chance as they were a matched pair and would be saleable if I did not like them.
Much more detail and ambience so they were a good buy.

Greetings,

While military gold pin E88C made by Tesla are nice valves, there are better valves that match the character of the DAC I, in my book. I could highly recommend the Russian 6N6P valves from the late 50s or early 60s with a square getter made by Foton factory. Those valves have the most gorgeous, sonorous & full mid that I heard from a low/mid mu, noval format tubes.

The other less relaxed alternative would be the 6N1P from the 60s or 6N5P from the late 50s. Those valves have a very dynamic sound character in our circuit and have nice and full mid bass.

S

[SW1X]

One more thing Martin, the 6N6Ps you had were from the 80s. Those valves have a much thinner sound character, with a slight tilt towards the top end.

S

[ovlov854]

Greetings,

While military gold pin E88C made by Tesla are nice valves, there are better valves that match the character of the DAC I, in my book. I could highly recommend the Russian 6N6P valves from the late 50s or early 60s with a square getter made by Foton factory. Those valves have the most gorgeous, sonorous & full mid that I heard from a low/mid mu, noval format tubes.

The other less relaxed alternative would be the 6N1P from the 60s or 6N5P from the late 50s. Those valves have a very dynamic sound character in our circuit and have nice and full mid bass.

S

I have actually ordered a pair of the 6n6P Fotons from the 60's that you previously recommended and am eagerly awaiting their arrival and have promised to share findings

[SW1X]

I have actually ordered a pair of the 6n6P Fotons from the 60's that you previously recommended and am eagerly awaiting their arrival and have promised to share findings

Sure, I hope that you will be pleased with the results. Please bear in mind that like everything else in audio it is a matter of careful matching with the rest of the system.

S

[diviy]

Not nos valves but Im loving the JJ ecc88 in my phono stage I had them from www.hotroxuk.com brilliant advice and service from them , My mate waiting on a mixed box of Russian Nos military valves on the way should be interesting ;);););)