The SOHA II Tube Thread
Dec 12, 2008 at 6:49 PM Thread Starter Post #1 of 99

bmwpowere36m3

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In the spirit of previous tube threads I'm starting this one for the SOHA II hybrid amplifier. I know it's a little early (prototypers just finished off their builds), but I'd like to get this started for interested users. The amplifier is based on the 12AU7 family of tubes and many others that have similar pinouts and electrical specs (ECC82, 5814, 5963, 12AT7, ECC81, 6DJ8, ECC88, 6922, E88CC, 8416, etc...).

So if users could list their experiances with all tubes they have used, a favorite/s and some description of their tone.
 
Dec 12, 2008 at 8:22 PM Post #2 of 99

holland

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used the following.

mullard 12at7
eh 12au7
rca 5963
eh 6922

favorite eh 12au7

rca 5963 a bit too lean
eh 6922 very nice, but not as full as the eh 12au7
mullard 12at7, too warm, bloated bottom end.
eh 12au7 nice well rounded sound, aggressive, yet behaved. works great with my choice of music, primarily death and black metal.

need to try 8416, always forget to buy some.
 
Dec 26, 2008 at 4:21 PM Post #3 of 99

runeight

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I have tried:

Ei Elite 12au7
EH 12au7
Amperex 8416
Brimar ECC82
GE 6680
JAN 6189
RCA 5963
RCA 6DJ8
JJ 6922
Amperex 6DJ8

The Brimar is too shrill. The 8416, 6dj8, and 6922 are very mellow. The rest are in between and your choice would depend on what you like to hear. My favorite of the 12au7 family is the RCA 5963. For me it has the best and clearest sound with perfect highs.

It is also fair to say that many of the 12au7 variations have not been broken in much. Everything could change if each set were run for 50 hours and then tested for SQ.
 
Dec 27, 2008 at 10:52 AM Post #4 of 99

V-DiV

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It might be useful to those building/balancing their system to know what headphones you used to gather these impressions since a pair of tubes could sound good with one set of cans but be a poor match for the sound signature of another.
 
Dec 27, 2008 at 4:20 PM Post #5 of 99

holland

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HD650, DT990.

Edit: Switched to using the Amperex 8416 now than the EH 12AU7. It has a bit more low end extension and softer upper end. Upper end variance is not that big, IMO. Still crisp, but not as forward.
 
Jan 3, 2009 at 7:20 AM Post #6 of 99

Hayduke

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The SOHA II will be my next amp project
smily_headphones1.gif


In addition to which phones you're using, posting what music you listen to mostly will also help (like Holland did).

I'm going to begin ordering parts sometime this weekend. I want to finish studying the build a bit first. I'll likely stick mostly to the 7007b BOM, but there are a few deviations I'm planning
wink.gif


This thread is going to be great for helping me pick a few tubes to start with.
 
Jan 3, 2009 at 4:31 PM Post #7 of 99

wolf18t

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Interesting thread. Still waiting for my SOHA II kit to arrive but in the meantime I ordered NOS Sylvania 5814A and Amperex Orange Globe 6DJ8 for tube rolling.
M493A.JPG




I'll let everyone know how they sound with my RS-1 and DT-880 in a few weeks if the build goes well.
 
Jan 3, 2009 at 4:44 PM Post #8 of 99

holland

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The Amperex 8416 is currently my favorite and I'm trying out the Amperex 6189 (Orange Globe). I'm still not quite sure what to make of the Amperex 6189.

BTW, in case people aren't aware. In addition to rolling the tubes you can roll the output transistors. I was using the 2SC3421 but switched back to the BD137. The 2SC3421 makes some tubes sound too shrill. It really didn't go well with the 5963, for instance. The BD137 (stock is BD139) adds more warmth, and is less pronounced in the highs. The 5963 works better with that, though still not quite my favorite as it lacks punch.
 
Jan 3, 2009 at 4:48 PM Post #9 of 99

KWS

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SOHA II will also be my next amp project and i have read through the details of it.
And most importantly,i can use one of my tubes collection,ie my TELEFUNKEN ECC82 12AU7 in this project.Of coz,i would let everyone know how they sound.
20080702_27a3c90cbfff11eae073FKyJsnSAC90a.jpg
 
Jan 3, 2009 at 5:38 PM Post #10 of 99

wolf18t

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Quote:

Originally Posted by holland /img/forum/go_quote.gif
BTW, in case people aren't aware. In addition to rolling the tubes you can roll the output transistors. I was using the 2SC3421 but switched back to the BD137. The 2SC3421 makes some tubes sound too shrill. It really didn't go well with the 5963, for instance. The BD137 (stock is BD139) adds more warmth, and is less pronounced in the highs. The 5963 works better with that, though still not quite my favorite as it lacks punch.


I will use 2SC3422 in mine. Wish they will not sound as shrill as 2SC3421.
 
Jan 3, 2009 at 5:58 PM Post #11 of 99

holland

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I don't have the 2SC3422. I've been meaning to buy 50 or so for various projects, but it's a bit expensive. I don't think they will sound thin. I pulled the 2SC3421 from my Dynahi, as other than BDs those are all I've got.

I believe some of the prototypers are using the 2SC3422. Ferrari definitely.
 
Jan 3, 2009 at 6:12 PM Post #12 of 99

Ferrari

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Quote:

Originally Posted by wolf18t /img/forum/go_quote.gif
I will use 2SC3422 in mine. Wish they will not sound as shrill as 2SC3421.


I have used Toshiba 2SC3422 in the amp I built for my GF. I would call it neutral, fast sounding, with slamming bass and slightly on the warm side.

This is in combination with Teflon interstage coupling caps and 6N1P-EB tubes in the front end.
smily_headphones1.gif
 
Jan 3, 2009 at 7:17 PM Post #13 of 99

wolf18t

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Quote:

Originally Posted by Ferrari /img/forum/go_quote.gif
I have used Toshiba 2SC3422 in the amp I built for my GF. I would call it neutral, fast sounding, with slamming bass and slightly on the warm side.

This is in combination with Teflon interstage coupling caps and 6N1P-EB tubes in the front end.
smily_headphones1.gif



Thanks Ferrari. This is quite the sound signature I'm after to complement my slightly thin and forward upper mids/highs RS-1. The coupling caps should be the Mundorf M-CAP Supreme (not the silver oil series, I'm not that rich
biggrin.gif
).

I have some high expectation from the Orange Globe. Read some good things about them. On the paper I think this Grado/2SC3422/Orange Globe combo should defenitly rocks with some good prog/classic rock material.
 
Jan 3, 2009 at 7:47 PM Post #14 of 99

bmwpowere36m3

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I've used:

* Electro-Harmonix 12AU7's

Listened with Senn HD580's and to music ranging from Pink Floyd, Led Zeppelin to Metallica, Alice in Chains, In Flames, AC/DC, to some classical. The EH tubes at first were a little harsh and very in your face, forward soundstage. As they burned in they've settled back, but still have a forward presentation. They have clear, defined highs, good midrange punch, and bass detail. I'd say the only thing they lack is maybe some more bass slam and midrange bloom, however like Holland has mentioned they sound wonderful paired with "Metal".

All the music I've listened to sounds good and much more detailed than any other amp I've had thus far... when I start rolling tubes I'll be looking for something with a "warmer" sound (for Floyd, Classical, etc..), as the EH's are fairly neutral compared to my "SS" Hybrid which was very "tubey" sounding and a little overly warm.
 
Jan 4, 2009 at 5:48 AM Post #15 of 99

Hayduke

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I realize I'm a newb, but I'll ask anyway
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How do you find suitable tubes? When I look at vendor's listings, there are thousands of tubes! I can find 12AU7 easy enough, but how do I find 6N1P-EB or RCA 5963 etc?

When I am looking at the tube vendor listing, can a 12au be any of these? The place I got my 19J6s from has 2 listings, 12AU7/A and 12AU7A RCA. I was gonna order some part tonight, but I might hold off until I'm sure about what I want/need. I might just call them on Monday as well.
 

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