[Designsfx]

@Isaacc7
Sounds like you have a good understanding of how tubes work- we should have a chat sometime regarding how/which families of tubes play into existing systems and their tonal influence when interacting with other components (should you be open to that). I’ve had much experience with tubes and how their voicings affect guitar amplifiers but rolling within components of an audio system in new territory for me.

 

[Isaacc7]

@Isaacc7
Sounds like you have a good understanding of how tubes work- we should have a chat sometime regarding how/which families of tubes play into existing systems and their tonal influence when interacting with other components (should you be open to that). I’ve had much experience with tubes and how their voicings affect guitar amplifiers but rolling within components of an audio system in new territory for me.

I like talking tubes! I have accumulated a fair amount of factoids about tubes as I searched for various permutations and whatnot but I really only know the basics as far as how they actually work. As far as the tonal stuff I'm a big believer in how tubes interact with the other parts of the amp and the headphones/speakers you are using. I think the discussions about what tubes sound like make the most sense in the dedicated amplifiers forums. Unfortunately my main amp is a unicorn so it isn't clear to me that my experiences will translate to other amps.

I like finding out about how people are using tubes, how did you discover the ones you're using now?

 

[Designsfx]

I’ll send you a pm as I don’t want to get out of the boundary of the thread (as mentioned above).

 

[OctavianH]

I’ll send you a pm as I don’t want to get out of the boundary of the thread (as mentioned above).

While I fully understand that you want to discuss privately at your understanding level, which is for sure above than mine, I think your discussions will be a tremendeous value for those who want to understand more. Maybe a new thread?

 

[Designsfx]

Maybe the ”Obscure TV tube users“ thread

As I wrote to you in my message, the underlying thoughts behind trying these tubes can be summarized by the following-
* With prices being what they are these days and availability in constant question I started wondering “why couldn’t other less popular tubes (or models meant for other purposes) be implemented for use in an audio application?”
* In knowing that I couldn’t possibly be the first person to ask this question I started reading through the old time tube manuals/handbooks to determine which tubes could be compatible with my application be it electrically or with the use of an adapter.
* Once I had a list of possible candidates (I came up with about 10) I started searching the web for applications of these tubes. This led me to quite a few DIY forums where people who design/build discuss tube properties and variants.
* After much reading I decided to take a chance on a particular tube (6BQ6GT) because it had been given favorable write ups in a few of these amp build projects and because they are in abundance.
* After looking over the pin out I found an adapter that would allow for its use- basically less than $60 for four with shipping. While hunting around I found two sets of quads- one advertised as being made in the early 50’s and another from the early 60’s. I believe the total cost of both quads (including shipping) amounted to no more than $50.
* Two weeks later I had both sets of tubes and adapters- time to try them out. The early 50’s set was manufactured by CBS/Hytron and after listening to them I really didn’t care for where it was going. Now that could have been they needed more run time or it could just be the tubes- either way I switched to the second quad which are early 60’s Sylvania. I could tell immediately these had more to offer and were going in the right direction.

I’ve been using these tubes for a little over a week now and they have turned out to be really nice tubes. Their sound quality has appreciated through use and they are providing qualities of tubes that I’ve purchased for much more money. With that said I think this worked out really well and I will definitely keep researching others.

 

[Designsfx]

 

[Toonartist]

Does anyone know what would be a reasonable lifespan of a Mullard EL38 tube. I know the legendary Mullard EL34 XF2 have along lifespan and wondered whether the EL38's were the same? Cheers

 

[AnyDave]

Does anyone know what would be a reasonable lifespan of a Mullard EL38 tube. I know the legendary Mullard EL34 XF2 have along lifespan and wondered whether the EL38's were the same? Cheers

I’m also debating how many backups to buy.

 

[Toonartist]

I’m also debating how many backups to buy.

Lol ... yeah. I have 4 double halos and a trough... debating adding a couple more pairs though..... maybe more depending on lifespan

Have you bought any from Langrex?!?

 

[AnyDave]

Lol ... yeah. I have 4 double halos and a trough... debating adding a couple more pairs though..... maybe more depending on lifespan

Have you bought any from Langrex?!?

Yeah, I have a single pair of the double halos from them. If you have 3 pairs, it’s probably a lifetime supply. But I understand the pull.

 

[OctavianH]

I’m also debating how many backups to buy.

I would decide that after I listen to EL39

 

[Toonartist]

Yeah, I have a single pair of the double halos from them. If you have 3 pairs, it’s probably a lifetime supply. But I understand the pull.

That's what I'm thinking. They're my daily driver... superb for most genres but especially classical and anything that benefits from staging / imaging. Pair up well with the RCA Red Bass 5691's

@OctavianH I have a pair of the EL39's as well. Great tubes but a little darker / less top end I've found compared to the El38's. I love the EL39's with the Meze Elites if I'm listening to something like desert blues from Tinariwen.

Edit. I don't know if I've been unlucky but all my EL39's have had lose bases and seem a little delicate compared to the EL38's.

 

[AnyDave]

That's what I'm thinking. They're my daily driver... superb for most genres but especially classical and anything that benefits from staging / imaging. Pair up well with the RCA Red Bass 5691's

@OctavianH I have a pair of the EL39's as well. Great tubes but a little darker / less top end I've found compared to the El38's. I love the EL39's with the Meze Elites if I'm listening to something like desert blues from Tinariwen.

Edit. I don't know if I've been unlucky but all my EL39's have had lose bases and seem a little delicate compared to the EL38's.

I need a pair of red base 5691’s. That’s definitely missing from my collection.

 

[Isaacc7]

I’m also debating how many backups to buy.

Heh. I have multiple sets of the el38 and e3375 as well. Of course my amp uses quads so it hurt a lot lol. Still, it's nice to know I'll have them for the rest of my life.

 

[Designsfx]

So trying a different quad of power tubes and rectifier combo this evening in my Lampizator TRP3 dac. I’ve had a mid 1940’s RCA 5R4GY sitting around for a couple of weeks now. This is a JAN CRC tube with black plates and double D getters- supposedly unused and came in an original box. Looked nice upon opening.

The quad purchased are Ken Rad 6F6G’s of the (I would assume) previously used variety. The seller stated he would attempt to match as closely as possible. The important part is that upon plugging them in they worked!

I placed these earlier today and let the equipment warm up for about 4 hours just to get settled before listening. As I’m listening now I’m noticing slight differences between both vs my regular playing tubes (RCA Globe 80 rectifier and Sovtek 6L6WXT+).

To stay on the topic I’ll focus on the 6F6G’s. Having no idea of their age or prior use I was surprised by what I heard at first. These tubes are definitely favoring the midrange and present a fairly neutral image. I wouldn’t call the presentation “rolled off” but there is a noticeable smoothing in the treble range, not quite as sparkly as with the Sovteks but present nonetheless.

The soundstage is perceived as being slightly narrower and definitely moved back. These are definitely not as bright as the Sovteks nor do they provide as much output as at my normal nighttime listening level I have my preamp turned up about 5 digits higher than usual. These tubes are very quiet though and provide no background noise.

I feel I should have left the rectifier unchanged in order to get a clearer picture of the differences but I think what’s written above provides a good outline. These tubes would work really well to tame down an overly bright recording or (in my case) a CD transport that seems to lean to the bright side a little more than would be desired. Overall they’re not bad tubes but overall I still prefer the 6L6WXT+.