Jens Rasmussen Leach clone group buy - Page 93 - diyAudio
Go Back   Home > Forums > Commercial Sector > Group Buys

Group Buys Members group buys

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 2nd December 2008, 07:55 PM   #921
diyAudio Member
 
brutepuppy's Avatar
 
Join Date: Jun 2008
Send a message via Yahoo to brutepuppy
HK compaired to Leach is no contest. The HK is a beautiful piece of art w/10 outputs per channel. One wonders why, with outstanding specs, it sounds as bad as it does. Its never been tweeked and is "as is" from the factory. Low level class A sounds OK, but as the volume goes up, it has the "transistor" sound to it.
Changing the caps may help the sound but I'll probably sell it before that happens.
__________________
  Reply With Quote
Old 3rd December 2008, 04:36 PM   #922
diyAudio Member
 
Join Date: Aug 2008
Default Searching for components...

Hi everyone! I'm continuing the search for components for the gorgeous boards that Tad provided for us. So far, so good, but... does anyone have a manufacturer / model number recommendation for the bias trimpot?? That's the only part I'm having a problem finding.

I wanted to let people know that Digikey has the Mills resistors for the output stage emitters at a very good price ($1.89/ea), once you order more than 10 pieces. The secret seems to be that they are listed under the parent company's name, Huntington Electronics, instead of Mills Resistor.

Best wishes,
Keith
  Reply With Quote
Old 3rd December 2008, 04:51 PM   #923
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
I don't have a PCB to measure, but it is almost certainly a three pin in line 3/8inch multi-turn with pins @ 0.1inch pitch. It might even be a four-holed pin layout to suit the staggered pin as well as the inline.
__________________
regards Andrew T.
  Reply With Quote
Old 3rd December 2008, 11:18 PM   #924
diyAudio Member
 
BobEllis's Avatar
 
Join Date: Sep 2003
Location: Upstate NY
It's a staggered lead only layout. Bournes 3299Y-1-502LF works. Mouser has them http://www.mouser.com/Search/Product...MYJ%2fUw%3d%3d
  Reply With Quote
Old 3rd December 2008, 11:45 PM   #925
diyAudio Member
 
Join Date: Apr 2007
Does anyone know if the Leach would work in balanced mode with 2 boards per channel. What I really mean is it a plausible project. I have this p1.7 all assembled and could use it for a good balanced input source. It is just kinda laying around with all the OTHER STUFF. I think most of you know what I mean. Tad
  Reply With Quote
Old 3rd December 2008, 11:53 PM   #926
AJT is offline AJT  Philippines
diyAudio Moderator
 
AJT's Avatar
 
Join Date: May 2003
Location: Palatiw, Pasig City
Quote:
Originally posted by tryonziess
Does anyone know if the Leach would work in balanced mode with 2 boards per channel. What I really mean is it a plausible project. I have this p1.7 all assembled and could use it for a good balanced input source. It is just kinda laying around with all the OTHER STUFF. I think most of you know what I mean. Tad
hello Tad, can't see why not....by operating in a balanced mode, you are effectively bridging your amp....


http://www.schuro.de/Daten/Burr%20Brown/DRV134.pdf
__________________
the best advertisement for a good audio design is the number of diy'ers wanting to build it after all the years....never the say so of so called gurus....
  Reply With Quote
Old 4th December 2008, 12:06 AM   #927
diyAudio Member
 
BobEllis's Avatar
 
Join Date: Sep 2003
Location: Upstate NY
That's commonly known as bridging. Works great, I used a BOSOZ to do that for a while. With an appropriate PSU and enough heat sinking you're looking at around a kilowatt or more into 8 ohms. (Did I just increase demand for another buy?)

Keep eye on the effect bridging has on the apparent load impedance - an 8 ohm load on a bridged pair of amps presents an apparent 4 ohm load. This is because the load sees twice the voltage that either amp swings, therefore drawing twice the current.

With reduced rail voltage you could probably handle a 4R load on your bridged amps. I'd be leery of trying 4R bridged at much more than 60V rails.
  Reply With Quote
Old 4th December 2008, 03:49 AM   #928
pchw is offline pchw  United States
diyAudio Member
 
Join Date: Apr 2006
Location: Fremont, California
Quote:
Originally posted by pchw
Keith, Ed,

2 kapton reserved for you.
All 9 kapton's are accounted for now.
I will post when I receive them.

Thanks!!
I got the Kapton tapes and will send out PM for the fellow members who expressed interested. For US, I will send priority mail + delivery confirmation. It is tight, but I think I can fit 2 packages into one priority mail envelop which only costs $4.80 up to one pound. Delivery confirmation is 0.65 which brings the domestic total to $5.45. Tony, I will need to bring your package to postal to get the estimate. We can discuss the type of mail that you want via PM. PM's follow :-)
__________________
- Fred -
  Reply With Quote
Old 4th December 2008, 11:30 AM   #929
diyAudio Member
 
Join Date: Apr 2007
I was thinking of using 50 -55 volt rails on the bridge unit. I then could build with 63 volt caps in the psu and afford to buy some Rifa's or the like. Those 100 volt caps are NOT cheap. Hook up the regulators I got from Bob for the frontend and then see how it goes. Should be a worthwhile project. Would be a quite large item though. I guess it would be very useful for a power hungry set of speakers with all that available juice. A small fan might be a nice addition on this job.

Anyone know how the beta test on the Super Leach is progressing?

Is there any interest out there for a long board configured to hold TO-247 devices. Something with just the power, drive, output and could be used with any project. Maybe 6 inches long with space for 6 devices. You could pair them up as you need. It would make building simple layouts very neat. I have not seen this anywhere before and could use some.

Tad
  Reply With Quote
Old 4th December 2008, 01:07 PM   #930
diyAudio Member
 
BobEllis's Avatar
 
Join Date: Sep 2003
Location: Upstate NY
IMHO, your RIFA caps are more likely to be noticed if you use the lower rail amps singly to drive mains (or mid/tweet). For home use, there isn't much need for 600+W headroom anywhere but the sub.

Your output board idea is interesting - perhaps an extender for the extended amp if you're driving really low impedance/reactive loads. It would also be nice for other designs.

A while ago I got some intended for an Aleph that have spots for 6 devices and can be cut in the center to make three device boards. Always a trade-off - spacing the devices a bit would provide better cooling, but make it harder to find suitable heat sinks.
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
WTB:2 boards from Jens Rasmussen Leach clone group buy mpmarino Swap Meet 0 12th January 2009 12:53 PM


New To Site? Need Help?

All times are GMT. The time now is 04:43 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2