[UntilThen]

I use #27 tubes driving Svetlana 6H13 like @gibosi But I don't use adapters the amp is made with 2.5 volt power for the #27s
and has 5 pin sockets.
I personally think the #26 and #27 are two of the best sounding preamp/driver tubes made. Use the #26 in my preamp.

You did offer to have 2.5 volts added to my amp but I said no because I'm afraid with too many choices, I will be driven over the edge.

 

[whirlwind]

You did offer to have 2.5 volts added to my amp but I said no because I'm afraid with too many choices, I will be driven over the edge.

Ha! Enough choices that it will drive you crazy

You have to admit though, that is one cool option!

 

[mordy]

Hi 2359glenn,
The option of #26 or #27 tubes is new to me. A quick look on eBay shows more 27s availble than 26s, and at lesser prices.
Is one type preferable over the other?
Is see that the 26 is 4 pin, 1.5V and 1.05A, and the 27 is 5 pin, 2.5V and 1.75A.
Are there any brands that sound better than others? Years?
Do you need a pair of them?
Are these the ones that gibosi is sifting through to get a quiet pair?

 

[Xcalibur255]

I cannot find a pair of 46 I like so I guess that whole thing is on the shelf for now.

Re-rolling all of the 45s did reveal that my noise problems are actually coming from one of the C3g, which I didn't think to suspect given their reputation. It also revealed that I find literally every single 45 ST tube I own to be boring and missing that special something after spending nearly two years listening exclusively to the Ken Rad globe UX-245s.

Only place to go from here is EML I suppose. I just wish I could know for sure that it will be safe for the tubes before spending $700.

 

[Xcalibur255]

@mordy
The common feeling on the 26 and 27 is that it's a pain in the butt to find ones that aren't noisy. Apparently the 26 is pretty fussy in terms of power supply design too.

 

[mordy]

@mordy
The common feeling on the 26 and 27 is that it's a pain in the butt to find ones that aren't noisy. Apparently the 26 is pretty fussy in terms of power supply design too.

Thanks

 

[2359glenn]

And since the #26 is essentially an AC version of the UX-201A, first introduced in 1925, these might be pretty good too.

The 201A is a very good tube but it has a thinner filament making it much more microphonic and noisy

 

[gibosi]

Are there any brands that sound better than others? Years?
Do you need a pair of them?
Are these the ones that gibosi is sifting through to get a quiet pair?

I am rolling 27's. While the 27's are indirectly heated, the 26's are directly heated, and therefore, it is not possible to roll them in the OTL with just a simple adapter and external heater. But of course, in an amp designed to run them, they would be plug and play.

And yes, a pair of these single triodes is necessary, one for each channel. I quite like the Westinghouse 27s. But I find that it is hard to separate SQ from quiet. The Westinghouse 27's are the quietest I have found. But perhaps if other brands were just as quiet, I might prefer another brand....

So yes, I have certainly found it to be difficult to find quiet 27s. That said, the OTL was not designed to run 27's. And I suspect that some tubes that I find to be too noisy might be fairly quiet in a Glenn "27" OTL.

Years? My experience is with production from the late 1920's and into the early 1930's. By the mid 1930's, mesh plates had been phased out and replaced by sheet metal plates. And also by the mid 1930's the globe bottle had been replaced with the ST bottle. The later tubes may in fact sound great, I just don't know... I have confined myself solely to mesh-globes.

 

[JazzVinyl]

Harman Kardon (Amperex} 12AU7 doing the honors for Stanley Clarke's "If This Bass Could Talk" album...

...Goodbye, Pork Pie Hat...

 

[UntilThen]

Harman Kardon (Amperex} 12AU7

I'm quite interested in trying these 12au7. How would you characterise the tone? Bright or romantic? Sizzling or laid back?

 

[JazzVinyl]

I'm quite interested in trying these 12au7. How would you characterise the tone? Bright or romantic? Sizzling or laid back?

They are super quiet, so no problems with popping or springy sounds.

They sound full and are a bit of both. Full solid bass, and lively mids and well controlled high end. The Amperex has a bit more growl in the bass than some of the Sylvania (again, gibosi's 'house sound' at play). Lower gain, so play well with 6BL/BX7...

I do find that all drivers in the GOTL appreciate 30 mins in, before they really reveal what they can do.

Some 12AU7's are priced too high. Be like Mordy...be patient and wait for some good prices.

 

[UntilThen]

Greetings @DecentLevi . It's been a long time since we last spoke. I saw your questions on Euforia thread but I wouldn't want to derail that thread by answering in it.

Yes, Glenn is still actively making amps for many, many satisfied customers. In fact the queue is quite long now.

As for how I felt about the Glenn OTL, I have enjoyed it every night since I got it 4 months ago. Yes exactly 4 months ago. I got it on the 12th of Dec 2017. Before Christmas !!! Best Christmas present ever.

Anyway, if you miss my mini review of the GOTL, here it is in comparison with the Woo Audio WA5LE.
https://www.head-fi.org/threads/2359glenn-studio.600110/page-1234#post-14048313

 

[UntilThen]

Some 12AU7's are priced too high. Be like Mordy...be patient and wait for some good prices.

Thanks for the reply but patience is not my virtue. If I did go in on a 12au7, it would be either a Telefunken or a Mullard.

 

[UntilThen]

Alright I have decided to go with good old Mullard and this M8136 is a special quality version of ECC82.
http://www.r-type.org/exhib/aai0263.htm

Now to order the adapter from Mrs Xuling..... slow boat from China. By the time it gets here, WW3 might have started.

And the seller's pitch for a faster sale...

"The NOS Mullard CV4003 (M8136) tube is a British military grade ECC82 / 12AU7 tube type. This 12AU7 tube has box plates which seem to improve resistance to microphonics and noise. They were produced in Mullard's Mitcham factory.


The Mullard CV4003/M8136 tube has a deep and expansive soundstage, with overall fantastic definition. The lows are defined while the mids and highs are liquid smooth, just leaning to the warm side of neutral."

 

[leftside]

The great thing about the GOTL is that you only need to buy ONE of these tubes. Brent Jesse has loads of info on the 12AU7's:
http://www.audiotubes.com/12au7.htm

I really like the Telefunken 12AU7's that I run in my Euforia DAC. A local Canadian dealer had some NOS/NIB that I purchased a while back. I am going to try the Mullards at some point as well though.