[LoryWiv]

Well, posted this question of Euforia thread bit no responses. Perhaps the smart people (all of you qualify!) on Elise thread can help clarify.

My question is about tube equivalencies and compatibility with Elise / Euforia. As best as I can determine 6L6 / 6V6 are similar to KT 66 / 88, EL34 is similar to KT77, and EL37 is similar to 7581. I have used adapters from Deyan to run KT 66, 77 and 88 as well as 7581A in Elise. Based on this compatibility is it also expected that any 6L6, 6V6, EL34 or EL37 would work equivalently well using this adapters I already have? Any landmines I should be watchful for? Thanks...still trying to educate myself about the depths, dangers and rewards of this tube rolling rabbit hole.

 

[OctavianH]

Hi mordy.

Given the EL34 is a good bit more powerful even than the EL12, I personally wouldn't want to even try it lol!!...these would seem to be much more for power amp use, not headphone!

Re. your initial finding of a 12N, the bass is indeed something special (as described more fully over at the Euforia thread...these multiple threads can sometimes be a pain in the proverbial LOL!).

And just wait 'til you have TWO of them pumping out their juice....I personally have never heard bass like it...ever!!

Which is why, as @DecentLevi also discovered, it can in fact take a fair while for it to settle down and allow the rest of the FR to catch up and open out!

And yes, the EL6 is basically the same as the 3(N), but twice the power output...as with the EL11 vs the EL12

Hi @LoryWiv , I am quoting this old post of @hypnos1 to aswer your question. As far as I know you can use 6L6 or 6V6 but I do not know if anyone from us tried, EL34 not and related to EL37 I have no idea. See above.

 

[LoryWiv]

Hi @LoryWiv , I am quoting this old post of @hypnos1 to aswer your question. As far as I know you can use 6L6 or 6V6 but I do not know if anyone from us tried, EL34 not and related to EL37 I have no idea. See above.

Thanks, @OctavianH. Is it the plate dissipation wattage that one references to assess how powerful a tube is or some other parameter?

 

[OctavianH]

It's a matter of the pin layout as far as I remember the previous discussions. I found something from the same @hypnos1 on the Euforia thread:

It's not just that the EL34 pin layout is different to that in the 7581A as we (and others) use it, but it's also different to all the KT family of tubes in that its grid#3 isn't linked internally with the cathode, but in the KTs/7581A it is. And so an amp that wants to use the EL34 and the KTs must make this link inside the amp itself. On top of that, in power amps, the 7581A, along with certain others in the 6L6 family has a higher rating, such that if configured for it can be pushed harder for greater output. BUT, if tubes with the lower rating are used in such an amp, the plate will most likely end up glowing red, and...!! Luckily, as our amps aren't driving these tubes anywhere near max, this isn't an issue for us anyway! However, as can be seen from the case of EL34 vs KTs, using tubes other than those specified by the manufacturer can have unexpected consequences (and possibly drastic ones, in other instances!

Source here:
https://www.head-fi.org/threads/fel...sheeps-clothing.831743/page-481#post-15297981

PS. I've just found a small website for some tube quickspecs here:
http://www.audiomatica.com/tubes/6sl7.htm

 

[LoryWiv]

It's a matter of the pin layout as far as I remember the previous discussions. I found something from the same @hypnos1 on the Euforia thread:



Source here:
https://www.head-fi.org/threads/fel...sheeps-clothing.831743/page-481#post-15297981

PS. I've just found a small website for some tube quickspecs here:
http://www.audiomatica.com/tubes/6sl7.htm

Thanks. @OctavianH. Approaching a case of the more I learn the less I understand. Thankfully, right now I'm back to "in spec." Tung-Sol 7236 with Brimar or Ken Rad 6SN7 / VT-231, and I must say results are quite enjoyable.I'll keep looking for musical nirvana w/o blowing up Elise or my headphones!

 

[OctavianH]

Currently listening to Harakiri for the Sky:



And a nice article, for those who about to read:
https://kenrockwell.com/audio/why-tubes-sound-better.htm

 

[OctavianH]

I have no idea why I always wanted to try this combination and never done it.

Well, not until today. I always felt that the russian re-issues Gold Lions KT77, being warmer than the KT66 clear glass, will be a good pair for the GE 6550A.
And indeed, these tubes are complementing somehow each other providing a very neutral sound, somehow towards solid state, clean and accurate. These are not spectacular for rock music, but I guess for some classical / operatic music might shine. Anyway, not a bad combo at all.

But what happens if we put the KT77s on the power slot for the GE 7581A? Well a lot of bass is coming, and a warmer and relaxed tone.

This is a good example of a tubey sound. Not bad, a little bit too much for my taste.

So at this point I said to myself "Which are ones of the cleanest drivers you have not listened in a long time?" and 3 answers came in my mind: Melz 6H12C, RCA 7N7 and the Ken-Rad VT-99.

And this is how I found an incredible combo. The Melz 6H12C are excellent drivers for the KT77s. What I hear here is much above the previous 2 combos. This combination is something I never thought about but it is a top class one.

When I received these KT77 I always considered them good as drivers. I have no idea why, maybe because of the form being smaller than other powers. It seems I was very wrong, these are for sure good powers for some neutral and detailed drivers. I will, for sure, give more attention to them from now on, as powers.

PS. Who was the high bidder on the Genalex NOS KT77 pair sold yesterday on Ebay by alibossa?

 

[LoryWiv]

And this is how I found an incredible combo. The Melz 6H12C are excellent drivers for the KT77s. What I hear here is much above the previous 2 combos. This combination is something I never thought about but it is a top class one.

When I received these KT77 I always considered them good as drivers. I have no idea why, maybe because of the form being smaller than other powers. It seems I was very wrong, these are for sure good powers for some neutral and detailed drivers. I will, for sure, give more attention to them from now on, as powers.

Is the Melz same as 6N12S? If so, I believe it has higher heater current then 6SN7's, correct? In other respects is it drop-in compatible in Elise driver sockets as long as one doesn't exceed total heater current powers / drivers of 6.6A or so?

 

[OctavianH]

Is the Melz same as 6N12S? If so, I believe it has higher heater current then 6SN7's, correct? In other respects is it drop-in compatible in Elise driver sockets as long as one doesn't exceed total heater current powers / drivers of 6.6A or so?

Yes, they are 0.9A. Here is a more detailed picture, ugly but sounding nice:

These are drivers with clarity and detail, neutral. So they are a very good combination to "tame" the warmness of the KT77.
The vocals and piano were outstanding.

(0.9A + 1.4A)*2 = 4.6A. I am fine.

 

[OctavianH]

Today I continued to roll drivers for the KT77 and the results were as expected.

And I've started with the beauties, the Ken-Rad VT-99 6F8G which are one of the most beautiful tubes I ever saw:

These are a good combo, warmer than the Melz one, but still detailed and nice. I like it, but since it did not brought anything new to the table I switched them with the Ken-Rad VT-231 black glass:

These are warm drivers for my taste, so the result was as expected. Same for the RCA VT-231 grey glass which were a better match than these but still too warm for me:

I tried also some Sylvania 6SN7GTB:

Then some RCA 5692. I never understood these tubes, even if some claim they are incredible and buy them at very big prices, honestly these fail me:

Both Sylvania and RCA were somehow unexciting, less details and recessed highs for my taste, so I replaced them with Psvane CV181T2 which are my favourite drivers for the Tung Sol 5998:

Surprisingly, these ones were also non exciting for me, even if these make wonders when used with Tung Sol 5998, so I switched them to the RCA 7N7:

And yes, magic happened, as expected and foreseen yesterday. These are close to Melz 6H12C. Very clean, detailed and neutral, a good match for the KT77.

At the end of the day, after I rolled all these drivers (10 pairs if I counted right), the best ones were the Melz 6H12C, RCA 7N7 and maybe on the 3rd place the Ken-Rad VT-99 6F8G. And this confirmed me that I know my drivers, exactly these ones were the ones I was expecting to match properly.

The reason behind my actions is that I expect to receive a pair of NOS Genalex KT77 which I was hunting for a long time. But in order to understand how to pair them, I have decided to put my new production russian re-issues of Gold Lions to work and see how they are pairing with some of my favourite drivers. And yes, we have 3 winners.

And in the end, the KT66 driving KT77, another magic combo:

This brings back that excellent guitar sound, but it sounds a little bit too warm for my taste. However, this one is a nice combo for electric guitar or classic rock.

 

[OctavianH]

And in the end, because there is always and end, I decided to give a second try to the russian KT77 driven by the GE 7581A.

And I liked them much more than yesterday. For progressive rock or recordings from the 70-80s which might sound thin or too analytical when using KT66 as powers these KT77 can bring a little bit of bass and joy to the table. I will keep these for a while, and keep close also the Melz 6H12C.

If I will drag a line after these 2 days, I would say that I learned the following:
1) The absolute combo for modern rock/metal with intense guitar passages is the GEC KT66 clear glass + GE 7581A. I never heard an electric guitar sounding so good.
2) For classical rock or older recordings where the production will sound thin compared to today's standards the KT77 adds exactly what is needed.
3) For classical or vocal music, where the guitar does not matter too much but the clarity and KT sound is desired, the KT77 + Melz 6H12C was the best I could obtain. The female voices or piano sounded very nice to me with these.
4) Very close from the previous option were the RCA 7N7 and the Ken-Rad 6F8G VT-99 when driving the KT77.

Well, that's what I was able to tell about KT77. I never try to describe too much. Interconnects, DAC and personal preferences matter. I just say a few words to help the other have an ideea about what a tube sounds like. But in my case I listen 99% to rock music, this means a lot of electric guitars. So my perception is biased by this genre.
More than this, I have some personal preferences which many might disagree. I do not like silver cables, they sound dry and lifeless to me. I use Chord Qutest with Incissive Neutral as filter and DH Labs Air Matrix as interconnects.

As a good example where KT77 + 7581A shines is my favourite Iron Maiden album, Seventh Son of a Seventh Son:



This album is a total masterpiece but it always sounded thin for me. With this combo I get those incredible guitars, in Infinite Dreams for example, while having enough bass and a holographic overall presentation. This album sounds magic, and it is a perfect example for point 2).

 

[LoryWiv]

Nice work, @OctavianH, you are an inspiration. Genalex vintage tubes do seem difficult to source and quite pricey, let us know how the vintage KT77's perform. I have some 1940's Ken Rad 6V6GT's on order to use as powers with Deyan's adapters. For now I'm back to a "conventional" combo. of Tung-Sol-7236 driven bt Brimar 6SN7GT, actually enjoying it very much. The analytic 7236 are balanced nicely by the Brimar's warmth!

 

[OctavianH]

Yes, this is exactly how I see them. The 7236 are somehow on the solid state and analytical side, and need warmer drivers. But they are incredible tubes. I have 2 pairs and I like them a lot.
On the other extreme, the Tung Sol 5998 is warmer but it has a precise and punchy bass. Those go well with neutral drivers and make a terrific pair to the Psvane CV181T2.

To make a small joke, The Tung Sol 7236 are the powers I see everyday because they are my desktop background on my PC:

So every time I open it, and I do it daily, I see this picture of the mighty Siemens C3g + Tung Sol 7236. Being a former Siemens employee this reminds me a little bit of the past.

PS. I have not worked in tube or electronics, but on telecom area where Siemens many years ago had a good name and portofolio.

 

[LoryWiv]

Have you ever had a day where everything just sounded GREAT? Had a work from home day today, fit in some tube rolling. First up was Tung-Sol 7236 with Brimar 6SN7GT, at first seemed overly analytic as noted but over time the stage, instrument separation and frequency extension became quite compelling, balanced by the slightly warmer leaning of the Brimars which added cohering layering of the individual instruments. Very nice with string quartets, piano trios and some classic tock. Next up was the big brother of @OctavianH's new production GL KT77, the GL K88, powered by vintage GE 7581A drivers. Overall this combination is more euphonic despite the treble being prominent, somehow it soars without sibilance. It's also a bit more of an exciting, enveloping sound and "tubey" in the best sense of the word, relaxing but rewards careful listening as well.
With some music the bass is a tad loose but I thinkto some degree that adds the warmth I'm enjoying.

Main conclusion: Elise is a beautiful and versatile chameleon, finding ways to deliver great sound with (almost) any tube set. It's been a fun day of enjoying music!

 

[OctavianH]

Today no rolling, I will continue for a while with the KT77 and 7581A until the NOS KT77 arrives, and then try to see if the NOS pair will add something to the table. And since Iron Maiden sounded nice yesterday, I decided to go back 2 years, from 1988 to 1986 and the "Somewhere in Time" album. It is indeed a little bit of loss of focus and detail compared to the KT66 and 7581A but there is also something I like about this.