Tube rolling thread | UltraSonic Studios

[OctavianH]

And the incredible GEC ATS25 blue glow. Damn, I love this.

 

[Krassi]

Thanks for this lovely thread with all those detailed infos about the perfect 807 tube!
i was really looking for exactly this since i was lucky to get my hands on a great 807/6sl7 Tube amp and was looking for some awesome tubes for this!

I have got a pair of new horn speakers loaded with vintage Coral drivers (BK 202 with Coral 10L-60, Fostex H425 with Coral M-100 and Coral H-70)
And was looking for something that makes them shine.

So i shot me 5x valvo QE06/50 tubes on the german-bay for the start (two smoked glass could be mullards) together with a nice nos 6SL7WGT SYLVANIA.
But of course tube rolling will be a mandatory for this new tube amp !

Since 807 are not so boutique prized as 300b it makes it lis ess bank braking to try some more.

So i stumbled on your description of the GEC ATS25 wich seems to be what i really really want to try!
I also followed your link to michael and lets see what he can offer.

i really cant wait to get my hands on this new tube amp and hope to share some insights about 807 tubes.

Great stuff keep up your work and enjoy the music!

 

[OctavianH]

Thanks for this lovely thread with all those detailed infos about the perfect 807 tube!

There is another great resource where I put some pictures to show construction of different 807 and equivalents here. Take a look maybe you will find something useful. I was not able to find enough information, I tried here to show them. I have 2 types of RCA 807, slightly different but not enough to picture there, so I put only the older one. Soundwise, identical, at least to me.

i was really looking for exactly this since i was lucky to get my hands on a great 807/6sl7 Tube amp and was looking for some awesome tubes

Can you tell us more about this great amplifier? Can we see it somewhere?

i really cant wait to get my hands on this new tube amp and hope to share some insights about 807 tubes.

Please do that, I am very happy someone else is enjoying the 807 with 6SL7.

Later edit:
Regarding Valvo, these usually rebrand Mullards or even russian tubes. For example here these look like my RSD branded russian 807. Not bad at all, but ATS25 will blow you away. Instead of ordering russian ones at 55 EUR I'll definitely go for RCA 807 which has deeper bass and sounds fuller. Even the highs are better, but it is not so sweet as the european counterparts. Show us some picture with your smoked glass ones. I do not have those.

 

[Krassi]

Hi!

Thanks for all the Infos!

Here is a picture from the 807 tubes. I should get them next week since they come from germany.
Really a bargain for 39 bucks all together and tested good.

Yesterday i did some more doomscrolling with google and found some more

-1x NOS RCA 6SL7GT smoky glass cheap from Croatia
-2x unlabeled NOS RCA 807 tubes for 19 bucks!


Well the Tube amp is still a mystery for me but its on its way from Poland and should arrive next week.
Regarding that Amp.. well i was really interested in a 807 amp after not being able to get a ultra amazing one from a guy from cologne (in the neighborhood).
That started my interest in 807 and i wanted to find someone who can build me one.

But suddenly i stumbled on this kleinanzeigen offer from poland after my daily hifishark, kleinanzeigen, bay search cycle
"boom headshot".. 380bucks for a very simple but great crafted amp with 2x 807 and 1x 6sl7... i was really amazed since its such a simple design with a minimum number of tubes in a great crafted case.

So my belly told me "go for it and lets buy this!" ... the person that build it seems to be an old guy with lots of knowledge about tube amps and after some wonky comunication with german to polish translation i got some infos about like 6 wats per channel and 8 ohms.

I have no clue what transformatiors are used but i guess those are not cheap chinese ones. Well no hashimoto, tango, hammond or similar but he told me it has no humming and sounds great.

Well with just 3 tubes it should be direct as hell

I already have a nice super simple super compact custom amp that a guy from germany built for me.
it uses cheap russian video tubes and can do anything from XLR in/Out, MiniXLR in, RCA in, Headphone jack and speakers! In a case that is half of a paper! I wanted it for my AKG K340 in the first place and speaker output was "just an extra"

And because i use this one for speakers only at the moment i have a tube amp only for my headphones.
It was a bijou tube amp prototype from the same guy that build an amp to drive the AKG-K340 to the mars and back ))

This thing can still go XLR in/out and RCA in and blast the crap out of my K-340 with 800ohm!
Its totally linear from zero to 100%!!

Holy sht since i never tried tube rolling this could be also interesting since it uses 4 tubes.
i Actually dondt even have a clue what tubes it uses ! i have a spare set for both amps since the guy really knew what he built and what tubes to use.

The black one is the headphone amp and the white one drives my speakers with 4 wats.. i was still to lazy to put another mahagoni wood knob on this one and still have a skweaking crap plastic knob still on it )

 

[OctavianH]

Hi!

Thanks for all the Infos!

Here is a picture from the 807 tubes. I should get them next week since they come from germany.
Really a bargain for 39 bucks all together and tested good.

Very interesting. I doubt those are Mullards but might be similar with these. The ones on the right I guess are RCA. We will see when you receive them and maybe take a better look on them. Let us know what do you think of each pair

Regarding the amps I have no idea, but I am very glad that I find more and more about 807 and others who might enjoy them as much as me.

 

[Magol79]

@OctavianH

I just got these as my first pair of 807s. Do you have experience with Brimars?

 

[OctavianH]

@OctavianH

I just got these as my first pair of 807s. Do you have experience with Brimars?

Ah, so you bought them. I was expecting this I have no Brimar here and I was watching them. Nope, you are the pioneer, let us know what you think.
I guess you will like these, on Euforia these should sound nice, if Euforia is how I imagine it to be.

PS1. I doubt you can go wrong with 807, but if you do, sell those to me.

PS2. I doubt all these manufacturers produced them, I think some of them rebranded. Here I found a picture of a different one with "Brimar" printed on the base which looks quite different:

I guess we need to investigate more in this area. Yours look close, but no identical with my RCA.

 

[OctavianH]

I was saying a few days ago that I have several pairs of RCA (or at least labelled) 807. I made some decent pictures of 2 different ones to show.

As you can see, bought have slight differences. I wonder what "MBA" stands for under the 807 square. On british tubes (GEC and Brimar) I've seen "foreign" mentioned and those were tubes rebranded. I think this is the direction we have to investigate, to see exactly what types are available, who made them and who rebranded them.

 

[hpamdr]

Long long time since no post...
After some months of test and listening Eternity and comparison with SS, Euphoria, and MoodWright KWA-150se with magnepan for main system..
I have selected some combos which i like a lot depending of music session... (The music types drives generally different sound engineers ways of working..)


For solo piano, organ music and large symphonic ensemble my choice goes to GU50 as output tubes and single NR73 in input... The GU50 need long burning times to loss the dry but after many listening hours it is keeping dynamic on steroid ... Crystal clear sound, precise, dynamic all that could make a SS lover agree that Tube amps are ultra-precise (Thx to Tomas !)

For jazz, pop and small ensemble EL39 or EL12sp and dual NR73 or (Viseaux) 6N7G gives great amplification factor and works with all headphone adding a bit of boost in low and medium... If i had to keep only one combo flavor, this is the one I like with everything (Music, Headphone, DAC)

For electric pop, acid jazz, trip hop ..... I like a lot EL34, 6P7S, (still EL39) as output and EL11, EL3N 6M5 or 6SL7 as input with HeedPhone. This add some euphonic and darker tone which make tube sound with a specific flavor that no SS amp can compete !

For very small ensemble with female voices, i like a lot EL32 or 6V6 as output and single 6BQ7A or rca VT-94 with T1 or HD800s this gives some romantic sound...

I still have many tubes combo to test. I finally stopped to get new tubes and just enjoy music a lot.
I currently think that Eternity is one of the best audiophile purchase i did in the last 10 years but if i did not put my feet with first 500 bucks Elise, my path could have been totally different...

 

[Krassi]

Well i really love to search like crazy once you find something interesting.
Starting point was the new set of big speakers and the weird idea "lets look out for a new tube amp that can drive them to mars and back"

Since i buy lots of stuff from yahoo Japan auctions you directly got totally blown away by those tons of sick vintage tube amps that are on auction all the time.
So you see lots of 300b and 2A3 and other weird stuff with freaking expensive Sansui Output transformers and lots of weird stuff.

And since a tube amp builder that i asked also directly wanted to build something with 807 i thought "maybe those are really good!"

I never thought about rolling tubes before because i was happy with the sound of my amps.
But with those really ok priced vintage 807 its really nice to instantly get lots of stuff to try without the risk of spending 200+++ bucks for chinese boutique stuff.

with a set of 3x different 807 and 3x different 6sl7 i should be able to try out lots of combinations!
And as you mentioned you got one Amp and can customize it to fit the mood or music with just changing the tubes!

I also hope they glow blue ! would be some nice moody acid lightning.

 

[OctavianH]

I currently think that Eternity is one of the best audiophile purchase i did in the last 10 years but if i did not put my feet with first 500 bucks Elise, my path could have been totally different...

This is a very strong statement which I think describes a lot your experience. Eternity is also one of my best purchases, alongside Final D8000 Pro and JCAT usb cards.

 

[OctavianH]

Friday Beerday, a good moment for a small change. I have decided to return, for a while, to GEC KT66 and see how these sound with the RCA 6N7G. I never had the chance to try this before. Let's see where this goes.

 

[OctavianH]

The previous combo was good, KT66 on this amp benefits from a warmer driver and this is what I did not had at the time I played with them in the beginning of last year. This gave me confidence to try more, so a natural choice for me was the Tung Sol 6SU7GTY grey glass. In my limited experience with grey glass tubes I always find them a little bit warmer and more euphonic than the clear glass counterparts. And yeap, good catch. Even if you already have your favourite combos it is always a good practice to revisit some tubes and try to pair them with something you have not tried at that time. You might have a surprise.

I will not hide that I will go back to KT88 just to see how these behave with 6SL7. I never tried that. Unfortunately I do not have a pair of GEC KT88 and I do not plan to invest in one. So I might try the 2 pairs I have here, a Shuguang Black Treasure and a Psvane one.

 

[hpamdr]

Just a remark about chasing 807 tube, keep also your mind opened to try a Russian tube "6p7s" you can get several tubes and do the best match yourself.

I got some from an Ukrainian vendor, he is specialized in Russian military electronic ( capacitor (like inside some amplifier), knob, rotary switches, .... tubes).
Eternity seems to work quite well with this as output tube, amplification factor is very good and i like those with rock and electronic music...

 

[OctavianH]

Just a remark about chasing 807 tube, keep also your mind opened to try a Russian tube "6p7s" you can get several tubes and do the best match yourself.

The 6P7S is the equivalent of the 6BG6 and I wanted to go this path but unfortunately these are not so easy to find cheap in Europe. There are 2 tube types I have in mind but never got to try 6BG6 (including the russian counterpart) and 6AR6. In the end I went for 807 and I am at the moment considering it my favourite output type. Since these are quite cheap and you can easily find in Europe 2-3 different manufacturers (including russian G-807 which sounds very good for the price), it was a good decision. Now, the 1M$ question is how is 6BG6 sounding compared with 807 on Eternity? Amplification factor is for both 8, heater Voltage and current the same (6.3V/0.9A) so... similar electrical specs, more or less?