Replacement 12AX7 for microphones?

[Groove Dog]

i'll tag onto this that i've found a NOS Amperex Bugle Boy 12AU7 locally for $35.

[Dr Funk]

I don't know about the Gemini, but I have an SE 5600 (MkI), and I swapped out the original 12AX7 for a Mullard - big difference! Smoother highs, meatier mids and lows. IOW, it doesn't sound Chinese any more.

These days it's one of the first mics I put up for vocals, and it certainly wasn't before the swap.

Cheers

Frank

[m. chan]

i love toobs

[kev2288]

Originally Posted by Dr Funk

I don't know about the Gemini, but I have an SE 5600 (MkI), and I swapped out the original 12AX7 for a Mullard - big difference! Smoother highs, meatier mids and lows. IOW, it doesn't sound Chinese any more.

These days it's one of the first mics I put up for vocals, and it certainly wasn't before the swap.

Cheers

Frank

What Mullard? There are many.

[iancrow]

Hi, i've had this issue forced on me by the factory fitted ECC83A tube going faulty in my SE Gemini (it was making a thump/click sort of noise every minute or so). I stuck in a old Marshall ECC83 i had kicking around and the random noises stopped. So now i'm looking to get something more appropriate in there.

My main concern is keeping the noise (of the hiss variety) low, i'd be interested in a valve that would slightly calm the hyped top end, and if it sound better in general that would be a bonus.

I have spoken to Hotrox (UK) and they suggested a Tungsol 12AX7/ecc803. I am prepared to go a bit more expensive than that if worth it.

So my questions are: Anyone got any valve suggestions for me? Would the Tungsol be quiet enough/any good for my requirements?

[siniarch]

Originally Posted by Dr Funk

I don't know about the Gemini, but I have an SE 5600 (MkI), and I swapped out the original 12AX7 for a Mullard - big difference! Smoother highs, meatier mids and lows. IOW, it doesn't sound Chinese any more.

These days it's one of the first mics I put up for vocals, and it certainly wasn't before the swap.

Cheers

Frank

I'm actually interested in which Mullard you put in there as well. I own a SE 5600 MKii.

I will probably also send a PM to BOWIE and see what he recommends. I've been loving the sound coming out of my SE, but it it's low-mids are definitely smooth but the highs could use some help. I would love to see what a new tube does to the highs.

[iancrow]

Originally Posted by iancrow

Hi, i've had this issue forced on me by the factory fitted ECC83A tube going faulty in my SE Gemini (it was making a thump/click sort of noise every minute or so). I stuck in a old Marshall ECC83 i had kicking around and the random noises stopped. So now i'm looking to get something more appropriate in there.

My main concern is keeping the noise (of the hiss variety) low, i'd be interested in a valve that would slightly calm the hyped top end, and if it sound better in general that would be a bonus.

I have spoken to Hotrox (UK) and they suggested a Tungsol 12AX7/ecc803. I am prepared to go a bit more expensive than that if worth it.

So my questions are: Anyone got any valve suggestions for me? Would the Tungsol be quiet enough/any good for my requirements?

Agh! Got the Tungsol, fitted it, and the fault came back. Tried the Mashall tube again and the fault occured, so the 5 hrs i ran it with the Marshall tube the first time without any probs lead me in the wrong direction fault-finding wise.

Now replaced the ECC82 and have it on test. Posting cos i didn't wanna lead anyone else on a false path.

[Richard Crowley]

12AU7/ECC82 is not interchangeable with 12AX7/ECC83 in many (most?) circuits. 12AX7 has higher gain and 12AU7 will not perform the same in a circuit designed for 12AX7.

12AX7 - Similar twin-triode designs

Note that there are only a small number of factories that make these tubes anymore. So many of those different "brand-names" come off the same assembly line. Maybe the quality is "tested-in" and maybe not. You never know with eastern European and Asian sources.

[iancrow]

Originally Posted by iancrow

Agh! Got the Tungsol, fitted it, and the fault came back. Tried the Mashall tube again and the fault occured, so the 5 hrs i ran it with the Marshall tube the first time without any probs lead me in the wrong direction fault-finding wise.

Now replaced the ECC82 and have it on test. Posting cos i didn't wanna lead anyone else on a false path.

Gutted - still doing it's intermitent click thing (about 20 per hour), so that's both tubes out of the equation. Anyone suggest anything else i can try to get this thing working properly before i resort to sending it off somewhere? (like the end of a cliff). Condensation issue maybe? Thoughts......anyone?

[iancrow]

Originally Posted by iancrow

Gutted - still doing it's intermitent click thing (about 20 per hour), so that's both tubes out of the equation. Anyone suggest anything else i can try to get this thing working properly before i resort to sending it off somewhere? (like the end of a cliff). Condensation issue maybe? Thoughts......anyone?

So, just to complete my tale of woe. Sent to SE. It was the diaphram. Cost alot, but now working.