Search found 648 matches

by Gold
Tue Mar 02, 2021 7:42 pm
Forum: Build
Topic: Phono Transfer System Construction Information
Replies: 206
Views: 251519

Re: Phono Transfer System Construction Information

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.
by Gold
Tue Mar 02, 2021 1:02 pm
Forum: Build
Topic: Phono Transfer System Construction Information
Replies: 206
Views: 251519

Re: Phono Transfer System Construction Information

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...
by Gold
Mon Mar 01, 2021 4:51 pm
Forum: Build
Topic: Transfer Filter / Neumann HT75 Replacement
Replies: 15
Views: 24391

Re: Transfer Filter / Neumann HT75 Replacement

I can't thank you enough Wayne. You saved my butt. The console sounds better already.
by Gold
Mon Mar 01, 2021 4:07 pm
Forum: Build
Topic: Phono Transfer System Construction Information
Replies: 206
Views: 251519

Re: Phono Transfer System Construction Information

MM carts are sensitive to termination capacitance. High and low capacitance cables, and length, should be considered when going for a target termination. I used to sell a kit 4 station dip switch and PCB with 24pF, 47pf, 100pF and 200pf polystyrene caps to cover a wide range of terminations. There ...
by Gold
Mon Mar 01, 2021 3:47 pm
Forum: Build
Topic: Transfer Filter / Neumann HT75 Replacement
Replies: 15
Views: 24391

Re: Transfer Filter / Neumann HT75 Replacement

It's done. It of course took much longer than I thought. That's kind of a good thing. If I accurately could estimate time I probably wouldn't have started in the first place. http://www.saltmastering.com/Console/EE-FilterSet-1.JPG http://www.saltmastering.com/Console/EE-FilterSet-3.JPG The faceplate...
by Gold
Fri Feb 26, 2021 6:58 pm
Forum: Build
Topic: Transfer Filter / Neumann HT75 Replacement
Replies: 15
Views: 24391

Re: Transfer Filter / Neumann HT75 Replacement

I fixed the response of Pre B LPF. It was all of my own doing as usual. Yesterday I fixed the Pre B HPF section which of course wasn't broken... I took another look at it today. I had the 680p and the 10n capacitor positions swapped on the right channel. Now it matches to a few hundredths of a dB li...
by Gold
Thu Feb 25, 2021 9:49 pm
Forum: Build
Topic: Transfer Filter / Neumann HT75 Replacement
Replies: 15
Views: 24391

Re: Transfer Filter / Neumann HT75 Replacement

Yes, that's about as close to 16 kHz as we can get on the LPF with E6-series capacitors. Great. I’ve never measured the HT75’s. I hope I’m not coming across as nit picking. I’m trying to learn. Do the same component tolerances account for the roll off being -14dB at an octave out instead of -18dB?
by Gold
Thu Feb 25, 2021 7:59 pm
Forum: Build
Topic: Transfer Filter / Neumann HT75 Replacement
Replies: 15
Views: 24391

Re: Transfer Filter / Neumann HT75 Replacement

It looks like the error in the Pre B HPF is an errant resistor. I went back and found better capacitor matches. It helped a little but not much. I'll have to go through the resistors again. I have a couple of questions though. I tried to use exact specified values for the capacitors and resistors. I...
by Gold
Thu Feb 25, 2021 4:16 pm
Forum: Build
Topic: Transfer Filter / Neumann HT75 Replacement
Replies: 15
Views: 24391

Re: Transfer Filter / Neumann HT75 Replacement

That's excellent Paul! The only one that was significantly different was: Pre B HPF Left: -14.00dB HPF Right: -13.04dB Yeah, I ran out of very tightly matched sets. I was selecting for absolute value as well as relative matching. That's why the gains also match from board to board. I could get a be...
by Gold
Thu Feb 25, 2021 3:32 pm
Forum: Build
Topic: Transfer Filter / Neumann HT75 Replacement
Replies: 15
Views: 24391

Re: Transfer Filter / Neumann HT75 Replacement

I have all four boards working and tested. Hopefully I can finish up the unit on Saturday. Since it's going in the case with the EE's the wiring shouldn't be too bad. I can recycle some of the wiring already in place. http://www.saltmastering.com/Console/Filter-3.JPG http://www.saltmastering.com/Con...