Aikido microphone preamp

[analag]

[quote author="Viitalahde"]I actually began to modify my Analag compressor, I just wanted to see what it does. Will report back on monday..[/quote]

If done correctly...you will have a little less tube noise. I usually tap into the B+ before it goes to the regulator. 75V is a good value.

analag

 

[Viitalahde]

[quote author="analag"]If done correctly...you will have a little less tube noise. I usually tap into the B+ before it goes to the regulator. 75V is a good value.[/quote]

Worked like a charm. :wink: I just reached for the first resistors I came across, and ended up having a 67v bias. I also put in a couple of Russian paper-in-oil caps that I just got (in the first stage) and I actually think the sound improved quite a bit.

I'm already thinking of an all-octal optical compressor. :grin:

 

[JCraft]

[quote author="12afael"]I´m not an expert on mic preamps but 36dB seems to be a little low, compared with 60 or 70dB on others preamps.

it run on class AB?[/quote]

Not really. A lot of older consoles/mixers had a fixed gain in this area. I have an Auditronics/Spectrasonics console I am restoring and the gain of the mic preamps appears to be about 38db. Remember the acclaimed V72 pres? I think they were around 40-45 db. A lot of the famous tube condensor mics would put out almost +4 depending on the source, so 30-35db is plenty. Modern ribbons are the ones needing 60+ db of gain when recording a nylon stringed guitar. I am working on building a 12AY7 based instrument preamp with only 22db of gain. When I asked my buddy (who designed the schematic based on my needs) if this was enough, he pointed out that a lot of guitars have an ouput approaching 1 volt. Learn something new every day.

 

[Kamel]

Hi all,

any idea or info about the 6sn7 russian substitute, 6n8s