[barontan2418]

Hi bt.

Looks like you've done the correct wire mod, so it should be OK. Do the heaters light up? And do the pins manage to go well down in the socket? If not, this would also stretch the anode wire a bit, especially as the 39's base is larger than the 38's. And pins are clean, of course?

And now I see you find the same thing @ZRW0 ...this is beginning to have me wondering just how Mrsx has configured her adapters!! I shall

h ave a go at trying to replicate what they might have done and find a solution, as well as ask them to send me info on their layout. So it might be best to wait until I find out what's happening here...CJ

Hi H1. Yes both valves light up perfectly and they are flush with adapter. My first thought was pos adapter was configured differently. I have no issue with top adapter not reaching ok. Thanks for help.
Also if I replace either EL39 with EL38 the side with 38 produces sound all be it very quiet the 39 side no sound.

 

[connieflyer]

Looks good erwan, I have to agree with you on the 5998, just like most tubes oh, they do require a lengthy burning. You really have to let these tubes settle in until they reach their better potential. Mine were NOS and they took a good while before they sounded at the top of their game. But definitely worth waiting for. Good luck with the e l 39 will probably have mine by next week, should be very interesting

 

[hypnos1]

Hi H1. Yes both valves light up perfectly and they are flush with adapter. My first thought was pos adapter was configured differently. I have no issue with top adapter not reaching ok. Thanks for help.
Also if I replace either EL39 with EL38 the side with 38 produces sound all be it very quiet the 39 side no sound.

This is very strange indeed..also with your anode wire seeming OK lol, compared to @ZRW0 . Am going to email Mrsx with details of my own config'n and ask why their own adapters aren't working as mine do...

 

[ZRW0]

Waiting for @hypnos1 's experiments, I switched back to one of my all time favorites, I didn't use for long: namely KenRad VT99 and TS 5998 CrhomeTops. (@DecentLevi how could you not love those ones ? )

(here used as preamp of my SS Speaker amplifier)

 

[barontan2418]

This is very strange indeed..also with your anode wire seeming OK lol, compared to @ZRW0 . Am going to email Mrsx with details of my own config'n and ask why their own adapters aren't working as mine do...

 

[hypnos1]

IMPORTANT NOTICE Re. EL39 ADAPTERS

OK guys...I feel real bad/disappointed that your EL38 adapters are not acting like my own, so rather than rely on PCB-based adapters from China, these EL39s deserve much better. And so I'm happy to make them for folks, using OCC silver and copper wires. I will also make them such that both the EL39 and the EL38 work in the same adapter. I estimate the cost will be about £12 per adapter, plus shipping. But, of course, there'll be a delay while I wait for the parts.

So anyone interested in my proposal, please let me know.

 

[Scutey]

Waiting for @hypnos1 's experiments, I switched back to one of my all time favorites, I didn't use for long: namely KenRad VT99 and TS 5998 CrhomeTops. (@DecentLevi how could you not love those ones ? )

(here used as preamp of my SS Speaker amplifier)

I'm definitely a fan of the 5998, it pairs really well with so many 6sn7 type in my experience, like you ZRW0, love KR VT99, also RCA/SylvaniaVT231, Psvane CV181-T2, as well as EL type tubes.

 

[OctavianH]

I put my noob hat and ask what are the construction differences between 5998 and 421A? I have to admit I think they look almost the same. How can I differentiate them?

 

[mordy]

Hi CF, DL,

Yes I agree with you CF, 5998 Chrome-tops are great tubes as well.

I'm the happy owner of WE-421A, TS-5998-ChromeTop, and CV2523.
I bought the WE-421A used, the others as NOS.

At first the 421A were far ahead all the other power tubes I had.
When I first tried the 5998 Chrome-top, I found them just "meh".

As my 421A were aging, I started to use the 5998 more and more, and actually found they started revealing their potential after hours and hours of burn-in.
They are now close to the performance of my 421As , yet a bit less holographic (unfortunately, one of my 421A has started to cough a bit when hot, some I'm using them less and less).

Regarding the CV2523, although I agree with H1 regarding the build quality of this tube, even after hours of burn-in, I never found they sounded as good as the 421A or as the 5998-Chrome-top.
To me they are just better than a good pair of 6080 or 7236, but not by that much. Given the price of 6080s or 7236s, the price of CV2523 isn't justified at all to me.

Cheers,

Erwan.

Hi CF, DL,

Yes I agree with you CF, 5998 Chrome-tops are great tubes as well.

I'm the happy owner of WE-421A, TS-5998-ChromeTop, and CV2523.
I bought the WE-421A used, the others as NOS.

At first the 421A were far ahead all the other power tubes I had.
When I first tried the 5998 Chrome-top, I found them just "meh".

As my 421A were aging, I started to use the 5998 more and more, and actually found they started revealing their potential after hours and hours of burn-in.
They are now close to the performance of my 421As , yet a bit less holographic (unfortunately, one of my 421A has started to cough a bit when hot, some I'm using them less and less).

Regarding the CV2523, although I agree with H1 regarding the build quality of this tube, even after hours of burn-in, I never found they sounded as good as the 421A or as the 5998-Chrome-top.
To me they are just better than a good pair of 6080 or 7236, but not by that much. Given the price of 6080s or 7236s, the price of CV2523 isn't justified at all to me.

Cheers,

Erwan.

Hi ZRW0,
"one of my 421A has started to cough a bit when hot".
I have had good luck restoring tubes that start to make loud popping noises by heating each pin with a 40W soldering iron for 30 seconds each. Just hold the tube vertically so that if something melts it will not flow into the tube (but really no such problems heating for 30 sec).

 

[mordy]

I put my noob hat and ask what are the construction differences between 5998 and 421A? I have to admit I think they look almost the same. How can I differentiate them?

There is a big debate if the 421A tubes are just the same as the 5998 but picked for higher conductance. Or maybe a special production run with a little different specs.
Some say that the clear top 5998 sound the same as the WE 421A.
One thing is sure, you can differentiate them by the price LOL!

 

[hypnos1]

Parts ordered for EL39/EL38 adapters...hope to make a start on them within the coming week...CJ

 

[myphone]

There is a big debate if the 421A tubes are just the same as the 5998 but picked for higher conductance. Or maybe a special production run with a little different specs.
Some say that the clear top 5998 sound the same as the WE 421A.
One thing is sure, you can differentiate them by the price LOL!

Some of the 421a and 5998 I have: from left 421a (1962), clear top 5998 (1958), chrome top 5998 (1957) and chrome top 5998 (1963).

421a and clear top 5998 are button getters (o-getter later 421a, > 1970's); chrome top are top getters.

Interestingly, the above 1957 and 1963 5998 have somewhat different structure (under the Domino plates).

 

[OctavianH]

Some of the 421a and 5998 I have: from left 421a (1962), clear top 5998 (1958), chrome top 5998 (1957) and chrome top 5998 (1963).

421a and clear top 5998 are button getters (o-getter later 421a, > 1970's); chrome top are top getters.

Interestingly, the above 1957 and 1963 5998 have somewhat different structure (under the Domino plates).

Many thanks @myphone for the visual comparation. I have a pair of the chrome tops from 11.55.

 

[hypnos1]

Hi H1. Yes both valves light up perfectly and they are flush with adapter. My first thought was pos adapter was configured differently. I have no issue with top adapter not reaching ok. Thanks for help.
Also if I replace either EL39 with EL38 the side with 38 produces sound all be it very quiet the 39 side no sound.

Hi again bt.

Have tested an EL38 in my own EL38 adapter with EL39 mod wire in place and it works perfectly. So at least I now know for sure that the adapters I will be making shall indeed be perfect for both tubes lol!
I simply cannot understand why the mod doesn't work in those Chinese adapters as it does in mine - it should do...and I'm not very impressed about that in fact...nor happy! Goodness knows what they've done in their design...
I'm so sorry for any inconvenience this may have caused folks...CJ

 

[connieflyer]

I had a problem with one of mrs. X adapters, and she did replace it for me. That was when she first switched over to the little PC boards in the adapters. Since that time I have not bought any more adapters from her. You would think that in order for that tube to function properly the leaves would have to be the same as they are in your adapter. I think at this point I would undo the wire, and redo it very carefully and making sure that contact is being made on both ends and the tube does not sit above the base of the adapter. There should be no reason electrically that if it works in yours it should work in mrs. X adapter., that is what I would do at this point