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12AU7 vs 12BH7 vs 6CG7

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SHiFTY

SHiFTY

Member
Joined 2002
Just wondering if anyone has compared these? Is there any clear winner? I am using a 12AU7 at the mo and have tried:

RCA 12AU7 cleartop
RCA 5693
Brimar 12AU7
Mullard CV4003
Sylvania 6??? (12AU7)
Philips Miniwatt ECC82
Siemens E82CC

To my ears, the Mullard and RCA 5693 sound the best; however I have heard people say that the 12BH7 will blow any 12AU7 out of the water. I have heard the 6CG7 is like a minituarised 6SN7 and is better again (although requires diff heater voltage)

Comments? :confused:
 
fdegrove

fdegrove

diyAudio Senior Member
Joined 2002
CRAMER VERSUS CRAMER

Hi,

however I have heard people say that the 12BH7 will blow any 12AU7 out of the water. I have heard the 6CG7 is like a minituarised 6SN7 and is better again (although
Click to expand...

A 12BH7A iso a 12AU7A will often sound better.

The 6CG7 exists as 12CG7/12FQ7 and is not quite the same asa 12AU7.
They may be still in production at the former Yugo factory but I need to check this.
I know this factory still produces the 12BH7A though as a Philips licensee.

Cheers,;)
 
Joel

Joel

Member
Joined 2002
joeltunnah.com
This is fairly dumb. A 12BH7 is not a 12AU7, etc. so, why shouldn't it potentially sound "better", or "worse" in any given circuit?
Are you using them both in the same amp, but adjusting all relevant circuit values to accomodate the different gain, currrent demand, plate resistances, etc?

I really would like one of you "shootout" guys to explain to me a statement like "I heard a 12BH7 will blow a 12AU7 out of the water.":confused:
 
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B

Burnedfingers

Member
Joined 2002
In my opinion the 12BH7 will sound much better than the 12Au7.

As Frank pointed out in an earlier post the 12BH7 in most cases is a plug in for the 12Au7.

The 6CG7/6fQ7 do sound like a 6SN7. The 6FQ7's in a RCA clear top will in most cases out shine the 5692's.

The 6FQ7/6CG7 is my favorite in the Aikido line stage as an input tube.
 
R

RockysDad

Member
Joined 2003
burnedfingers said:
In my opinion the 12BH7 will sound much better than the 12Au7.

As Frank pointed out in an earlier post the 12BH7 in most cases is a plug in for the 12Au7.

The 6CG7/6fQ7 do sound like a 6SN7. The 6FQ7's in a RCA clear top will in most cases out shine the 5692's.

The 6FQ7/6CG7 is my favorite in the Aikido line stage as an input tube.
Click to expand...


I also like the 6FQ7/6CG7 in the input stage of the Aikido pre. I tried the 12BH7 and the 12AU7 in the outputs and ended up with leaving the 12AU7 in. The low end seemed a little more full compared with the 12BH7. Using 12AU7 in the input wasn't as clean sounding as the 6FQ7/6CG7. Using 12BH7 in the input was nice but the 6Fq7/6CG7 was even better. As you can see, these were the only tubes I had on hand and tried every combination possible...

I also tried the 5963 in the DIY Paradise simple pre circuit and ended up thinking that the sound was not real clean in the upper frequencies dispite having a full bottom end. Tried them in the Aikido but couldn't get the hum out, DC heaters and all.

These tubes all have different flavors and the bottom line is to use whatever sounds good to you no matter what the opinions of others are.
 
Geek

Geek

Member
Joined 2004
Depends on the circuit configuration.

12BH7 will sound a little weak in the mids, with solid bass and clear treble in grounded cathode. However, make it the top tube in any totem pole and you have a clear winner :)

12AU7 has a sound people love or hate. It has a sweet spot in grounded cathode where it has great HiFi qualities, but you have to burn it hot. Used as a mu follower, it makes a nice sounding bass guitar linedriver that I dare anyone to show me better (for tone, Z is kinda ick ;) .

6CG7/FQ7, I have yet to hear a bad configuration for it. It's just a darn great tube :)

(all this is my HO of course)
 
L

lndm

Member
Joined 2006
Running a 12AU7 at low current (around a couple of mA), I have found some to be a little bass heavy, possibly tending between a little syrupy rich in the mids (RCA) to a little muddy (Mullard). There are too many variables here to draw a conclusion, but I prefer not to run them lean.
 
ray_moth

ray_moth

Ex-Moderator
Joined 2004
I looks wrong to me to see 6CG7/6FQ7 lumped together, as though they were the same. I know both are supposed to have the same electronic characteristics as the 6SN7 but the 6CG7 is considered to be inferior. It's reputed to be variable in performance from one example to another, while the 6FQ7 is much more consistent.
 
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