Tube Rolling Help

[poppachubby]

Hey Everyone. I have bought 2 NOS 12AX7 tubes for my EICO. It currently has all of its original Mullards. That's 4 - 12AX7's and 1 - 6X4 rectifier.

I am curious how location will effect, or not effect the result. Is there a best way to do this? I would assume that with one pair, I should try and maintain balance between the channels in conjunction with the Mullards. So one of each per.

Any thoughts on this, or should i just get in there and try whatever.

[blackraven]

Pops, you want to have the same brand and model tube for each channel. Different brand tubes will sound different. Now I roll different brand and model tubes in my preamp and DAC to get the sound that I like but each channel has the same tube.


You can put different pairs of the 12AX7's in as long as the channels are matched. Play aroud with the ;positions as it may change the sound and see what sounds the best.

[poppachubby]

Pops, you want to have the same brand and model tube for each channel. Different brand tubes will sound different. Now I roll different brand and model tubes in my preamp and DAC to get the sound that I like but each channel has the same tube.


You can put different pairs of the 12AX7's in as long as the channels are matched. Play aroud with the ;positions as it may change the sound and see what sounds the best.

Thanks, sounds good! I'm going to check in the manual to verify. I'll let you know how it goes.

[Feanor]

Pops, you want to have the same brand and model tube for each channel. Different brand tubes will sound different. Now I roll different brand and model tubes in my preamp and DAC to get the sound that I like but each channel has the same tube.


You can put different pairs of the 12AX7's in as long as the channels are matched. Play aroud with the ;positions as it may change the sound and see what sounds the best.

Ditto BR's comments, basically.

My Sonic Frontiers uses six twin triode 6922 tubes. Each channel use three tubes, one for each function: input buffer, gain, and cathode follower. I used identical pairs for each function, but it so happens that I use different makes and models for the different functions. There is no problem with this. In my case the most sensitive position is the gain, the next the input, and least significant for sound is the cathode follower.

[poppachubby]

OK, I was wrong. There are indeed 5 12AX7's and 1 6X4 creating 3 tubes for each channel. Just like you said Feanor.

I swapped out the gain and what a difference. I still need to listen more. My tech is a mod on the Yahoo EICO group. I think I'll put a post in over there.

[poppachubby]

Wow. I only have a couple of options due to the rectifier tube. In one position the music is way brighter with heightened detail. Sonny Rollins - The Essential RCA Years, The Bridge clearly has finer detail most notable in the higher frequencies. The ride cymbal really stands out as does rhythm and lead guitar. When in the other position, there is a warmer quality and some rolled off highs.

Right now, the tenor sax sounds great with some added brightness, so I think I'll leave it for now. I can't believe the difference. I switched back a few times on a somewhat familiar recording, but then to be certain switched to something I know well.

[blackraven]

Pops, you could drive yourself crazy tube rolling. I've bought several pairs of 1960's and 1970's NOS tubes as well as different type tubes as my VA gear can take 2 different tubes. I've got 4 more pairs that I'm going to try just to see the differences in sound. I've found each has its stregnths and weaknesses. And some pair well with certain other tubes.

[E-Stat]

Pops, you could drive yourself crazy tube rolling.

Ditto! I've got a good stock of various NOS small signal tubes for my stuff. As for flavors of the 12AX7, quite a few can be found here.

rw

[poppachubby]

Let me ask this. Was your most expensive 12AX7 worth the price? My Mullards are all long plate originals, quite valuable and sound great.

Edit. I found out the function of my tubes. 1/2 are for low level inputs. 3/4 are for high level inputs. 5 is an output tube and 6 is obviously output/rectifier.

I am not using the phono stage of the EICO, so it would seem changes to the high level and output are my main options.

[blackraven]

Pops, my most expensive tubes are a pair of old Mazda/Brimar 6CG7's (which replced my Russian 6N1P's) at $80pr and the price is going up because there is only one dealer that has a limited supply. They are my best sounding tubes, but price does not always mean it will sound the best. I bought a pair of 1960's Sylvania 6CG7's for $22 and they sound nearly as good but in a different way.

[Feanor]

Let me ask this. Was your most expensive 12AX7 worth the price? My Mullards are all long plate originals, quite valuable and sound great.

Edit. I found out the function of my tubes. 1/2 are for low level inputs. 3/4 are for high level inputs. 5 is an output tube and 6 is obviously output/rectifier.

I am not using the phono stage of the EICO, so it would seem changes to the high level and output are my main options.

You can pay plenty for rare NOS tubes. I haven't checked out the 12AX7, but my gain stage 6922 are Amperex USA white label 'PQ' that cost me $86 the pair, used, i.e. they weren't NOS as in "new old stock". Tube Depot sells what are presumably NOS versions of the same model for US$190 each, (see here). Top buck is paid for NOS Siemens CCa 6922s, like $400 each if you can find them.

[poppachubby]

Top buck is paid for NOS Siemens CCa 6922s, like $400 each if you can find them.

Good lord.

Pops, my most expensive tubes are a pair of old Mazda/Brimar 6CG7's (which replced my Russian 6N1P's) at $80pr and the price is going up because there is only one dealer that has a limited supply. They are my best sounding tubes, but price does not always mean it will sound the best. I bought a pair of 1960's Sylvania 6CG7's for $22 and they sound nearly as good but in a different way.

I have been researching the Brimars. They sound crazy. So far I have experienced some nice results. The Mullard rules the output, there was no competition. But as far as the high level tubes go, the GE's (Motorola) had quite a bit to offer. Fun stuff, I am going to leave in the GE's for a few days and get a thorough feel for them. Definitely worth the 8 bucks.

[blackraven]

Pops do a lot or research online. There are a lot of user reviews in the various audio forums about your tubes. I found a guy who is going to send me some NOS RCA Clear tops and NOS Sovteks to try.

[poppachubby]

Pops do a lot or research online. There are a lot of user reviews in the various audio forums about your tubes. I found a guy who is going to send me some NOS RCA Clear tops and NOS Sovteks to try.

I was going to say, if you have any pairs you don't want I'll consider buying them raven. I have been looking online for a couple of days now. There's alot available...

[blackraven]

Pops, when I'm done rolling tubes, if there are any that I don't like, I will just give them to you.

[poppachubby]

I am on the market for a matched pair of NOS 6SN7's for my Golden Tube. Hoping to hear some experience based advice or reviews. My budget is no more than $150/pair. I have been looking on audiotubes.com, such an impressive inventory but a little daunting. I want something with solid midrange and an open top end, bass isn't my focus here.

I'm looking hard at a pair of RCA blackplates from the 40's, GT variety.

The other question I have is for my power tubes. They are 6L6. How much improvement will I realise if I get a better NOS set, versus a typical current production set?

[Feanor]

I am on the market for a matched pair of NOS 6SN7's for my Golden Tube. Hoping to hear some experience based advice or reviews. My budget is no more than $150/pair. I have been looking on audiotubes.com, such an impressive inventory but a little daunting. I want something with solid midrange and an open top end, bass isn't my focus here.

I'm looking hard at a pair of RCA blackplates from the 40's, GT variety.

The other question I have is for my power tubes. They are 6L6. How much improvement will I realise if I get a better NOS set, versus a typical current production set?

PC, here are a couple of links you might find useful -- if you haven't discovered them already:

• http://tdsl.duncanamps.com/tubesearch.php
• http://www.tubedata.org/
• https://www.tubeworld.com/index_high.htm

Duncan Amps and Tube Data are info; Tube World has info and also sells tubes.

There are plenty of 6SN7 for sale on eBay of course. One seller I bought from two or three times is "restless_nomad" who seems to be very reliable.

[dean_martin]

Try a pair of RCA 7025s in place of the 12AX7s (not sure what positions they'd work best in your Eico, but should be fine as long as they're "mirrored"), especially if you like shimmering cymbals and top-end air.

[blackraven]

Pops, here's a local store that I have bought vintage tubes from. They have a number of black plate RCA 6SN7's. I don't no what year they are but give them a call and talk to Chelsea.

http://tctubes.com/6SN7-ECC32-5692-VT231.aspx

[blackraven]

Pop's, here's another place that has the 1940's RCA's but its in Taiwan and they ship to the U.S.. I've been thinking about buying some Tong Sols and RAytheon's from them.

http://tubes.tw/shop/product_info.ph...roducts_id=316

And this Guy is also a good place for tubes, Email him, he is very knowlegeable-

http://pages.prodigy.net/jimmcshane/tubes.htm

[poppachubby]

Great! I'll get back to you guys once I've scanned everything.

[poppachubby]

OK I've got my input tubes ready, a matched pair of Sylvania chrome domes...



I'm still deciding about the output tubes, NOS vs. new mostly, thoughts?

[poppachubby]

Well I picked up my 6SN7's last night. This guy was a real tube junky and had about 6 different tube amps, real vintage stuff. Sherwood, Fisher, EICO and Stromsburg.

He sold me 6 NOS Sylvania chrome domes. 2 perfectly matched pairs and a third pair that's quite close. I owe my tech a pair, so he can have number three (sorry Dan). I only paid $40 USD which I'm really happy about. I have seen them online for as little as $40 for one pair and as much as $65/70.





He also gifted me a single 6L6 Delco black glass tall boy. It's a stunning looking tube, it tested NOS. I think I have found a mission, to try and find another 5 of these for my amp. Does anyone know what they sound like? I'm going to try and ask Brent Jesse about it.