Search found 263 matches

by ricardo
Tue May 31, 2016 7:53 pm
Forum: Pro Audio Design
Topic: was HYPEX amps cheap surround system
Replies: 59
Views: 76063

Re: HYPEX amps

I've got a similar requirement. I want 8+4 channels for a Periphonic (with height) Ambisonic Surround system. I've got the 8 speakers and have designed the subs (4 off) and how to mount the speakers to the ceiling. After ooing & aaing etc. I concluded it would be simplest & cheapest to buy s...
by ricardo
Fri Mar 25, 2016 4:44 am
Forum: Build
Topic: Dual Class-A Line and Headphone Output Board Construction Information
Replies: 133
Views: 505340

Re: Dual Class-A Line and Headphone Output Board Documents

You can buy sealed heat pipes, but over kill for your project. (I never used one). [edit] not as expensive as I remember. here's one for < $4 in onseys. http://media.digikey.com/Photos/Advanced%20Thermal%20Solutions%20Photos/MFG_ATS-HP-F5L200S35W-026_sml.jpg http://www.digikey.com/product-detail/en...
by ricardo
Thu Mar 24, 2016 6:07 am
Forum: Build
Topic: Dual Class-A Line and Headphone Output Board Construction Information
Replies: 133
Views: 505340

Re: Dual Class-A Line and Headphone Output Board Documents

I had never heard of a heat pipe. A quick search turns up a tube filled with liquid. I think a home brew heat pipe is asking for trouble. If you ever get a chance, don't hesitate to have a play with one. :D The heat transfer is at 'sorta the speed of sound' in a heat pipe. The bottleneck is always ...
by ricardo
Tue Mar 22, 2016 9:19 pm
Forum: Build
Topic: Dual Class-A Line and Headphone Output Board Construction Information
Replies: 133
Views: 505340

Re: Dual Class-A Line and Headphone Output Board Documents

I've done experiments with heatpipes to get heat from speaker units to a heatsink on the external back of the cabinet. This was to reduce thermal compression from Cu coils heating up. Only worthwhile on the midrange unit of a big 3 way speaker. It would be very useful in a small 2 way but the cost w...
by ricardo
Tue Mar 22, 2016 7:29 am
Forum: Pro Audio Design
Topic: A Low Noise Balanced Input Moving Coil Preamp Using the ZTX851
Replies: 499
Views: 772777

Re: A Low Noise Balanced In Moving Coil Preamp Using the ZTX

I'm seriously entertaining the thought of using regular epoxy or JB-Weld. I used Super-Glue one time on LEDs and I think it degraded them. I've used hardware store Araldite and it works well but I didn't find any advantage over H/S compound and you couldn't take it apart if you had too. I think the...
by ricardo
Tue Mar 22, 2016 6:39 am
Forum: Pro Audio Design
Topic: A Low Noise Balanced Input Moving Coil Preamp Using the ZTX851
Replies: 499
Views: 772777

Re: A Low Noise Balanced In Moving Coil Preamp Using the ZTX

I've used a small piece of Cu cut from pipes to clip two transistors together, gunking with heatsink compound and finishing of with a bit of heat shrink for quick & dirty applications. This was a ribbon mike 'cloudlifter' type device for ribbon mikes where it was necessary to keep Vbe matched. ...
by ricardo
Tue Mar 22, 2016 6:38 am
Forum: Pro Audio Design
Topic: A Low Noise Balanced Input Moving Coil Preamp Using the ZTX851
Replies: 499
Views: 772777

Re: A Low Noise Balanced In Moving Coil Preamp Using the ZTX

I've used a small piece of Cu cut from pipes to clip the transistors together, gunking with heatsink compound and finishing of with a bit of heat shrink for quick & dirty applications. The application was a ribbon mike 'cloudlifter' type device for ribbon mikes where it was necessary to keep Vbe...
by ricardo
Fri Jan 29, 2016 3:18 pm
Forum: Build
Topic: Phono Transfer System Construction Information
Replies: 251
Views: 6535219

Re: Phono Transfer System

The platter is isolated from the arm. The platter (via its bearing) should really be connected to the cartridge case / pickup arm. The stylus on vinyl generates static electricity which needs to be leaked away if it's not to generate a click sometime when it discharges. The stylus should be connect...
by ricardo
Mon Jan 18, 2016 9:38 pm
Forum: Pro Audio Design
Topic: A Low Noise Balanced Input Moving Coil Preamp Using the ZTX851
Replies: 499
Views: 772777

Re: A Low Noise Balanced In Moving Coil Preamp Using the ZTX

While I don't expect input noise current to be much of a problem in a MC preamp it might reveal a larger difference between the purpose engineered low noise devices (with higher beta) and re-purposed low Rbb devices. A revealing test might be to look for the total noise difference between input sho...
by ricardo
Sat Jan 16, 2016 5:03 pm
Forum: Pro Audio Design
Topic: A Low Noise Balanced Input Moving Coil Preamp Using the ZTX851
Replies: 499
Views: 772777

Re: A Low Noise Balanced In Moving Coil Preamp Using the ZTX

They did have small Rbb' but you had to select for 1/f noise. Should point out that the killer with these medium power devices was popcorn noise (like you had on LM4562 et al) rather than strict 1/f But my small experience suggested that in 1980, they were correlated for these devices. AoE 3rd Ed ....