Pro Audio Design Forum

Wayne, I didn't want to make the scans so big you couldn't see the whole circuit. I can see the component values aren't readable that way. I could post the full size version for download if that would be better. Anyway R20 is 56K. That's the first resistor at the input between each end of the coil i...

Here is a scan of the transformer less preamp that is used with 1/2" heads. I'll scan the 1/4" preamp soon.

I didn’t think the Telefunken M10 had a standard set of electronics. I had one in a Neumann SP66 console. The playback electronics were manufactured by an RFT company that wasn’t Neumann. I forget which one. That setup didn't sound as good as the M15 which sounds fabulous. I’ll have a chance to scan...

My machines all have the correct heads for the given electronics. The machines have been completely restored and gone over by Dan Zellman and Bob Shuster. Both are factory trained Studer technicians with decades of experience servicing them.Nothing is broken. The machines work like new. I’m looking ...

I have a sheet with the impedance of the heads in Henries. The heads on each machine are a different impedance IIRC. I'll scan both preamp versions. I'm thinking of this more as 'proof of concept' than trying to get a finished build.

I thought the main determining factor would be the impedance of the head. I realize the EQ section doesn’t have provision for adjustable low frequency and hight frequency adjust but that can probably be worked around. The 1/4” machine uses a preamp with a step up transformer. The 1/2” and 1” use tra...

I have three Studer A80VU Pre tape machines. I’ve never been entirely satisfied with the sound of them. After thinking about and listening to the machines for years I think the source of my discontent is the cable run from the headblock to the electronics. The reason I think that is because the aspe...

My memory may be faulty but I think I was still using a Shure SE20 preamp when I tested the AT150MLX. That preamp was mounted on the back of the lathe under the tonearm. Not much more than a foot. I was also using RG59 coax cabling so I think I started with little cable capacitance.

Bill, I'm not sure what those graphs are showing could you explain them a little? I have an AT150MLX. I got it because it was described as a Shure V15 replacement. I hope I am not poking the bear when I say I found it painfully bright. I tried taming it with added capacitance but no luck. It was lik...

I can't thank you enough Wayne. You saved my butt. The console sounds better already.