View previous topic :: View next topic |
Author |
Message |
dvh99
Joined: 25 Dec 2009 Posts: 2158 Location: nederland
|
Link Posted: Sun Aug 21, 2011 5:35 am Post subject: this is what can be done with marquee heatsinks :). |
|
|
hybrid amp biased in 60w class a (it gets hot!!).
buz900/905 output stage.
_________________ 1 answer always poses multiple questions.
marquee 9500ultra HD10L moome hdmi1.3 v3+ some mods.
|
|
Back to top |
|
|
RayN999
Joined: 25 May 2010 Posts: 207 Location: Minneapolis, MN
TV/Projector: Sony VPL-VW60 and Toshiba 65H84 CRT RPTV
|
Link Posted: Wed Aug 24, 2011 12:59 am Post subject: |
|
|
Is this your own design? Or something you found somewhere? Glowbottle amps are always of interest to me.
Details, I want details!!
Ray
_________________ Ray Nelson
N9QBV
|
|
Back to top |
|
|
dvh99
Joined: 25 Dec 2009 Posts: 2158 Location: nederland
|
Link Posted: Wed Aug 24, 2011 1:52 am Post subject: |
|
|
it is from john broskie from the glassware website.
this is called the moskido, it has the aikido driver stage with the 6sn7 and 6sl7 tubes and a mosfet output stage with an added autobias which does wonders.
this amp is sounding amazing but i warn you that after you build an amp like this you will need to upgrade all the lesser parts.
i am hearing details now from records i never heard.
Description: |
|
Filesize: |
15.07 KB |
Viewed: |
9453 Time(s) |
|
Description: |
|
Filesize: |
17.58 KB |
Viewed: |
9447 Time(s) |
|
Description: |
|
Filesize: |
15.38 KB |
Viewed: |
9439 Time(s) |
|
Description: |
|
Filesize: |
20.1 KB |
Viewed: |
9429 Time(s) |
|
_________________ 1 answer always poses multiple questions.
marquee 9500ultra HD10L moome hdmi1.3 v3+ some mods.
|
|
Back to top |
|
|
dvh99
Joined: 25 Dec 2009 Posts: 2158 Location: nederland
|
Link Posted: Wed Aug 24, 2011 1:54 am Post subject: |
|
|
oh i might add that you will need huge heatsinks cause this amps produces a lot of heat!!!
go for 0.3C/W or better.
and add fans, i will do this later as the entire case gets too hot for the touch.
_________________ 1 answer always poses multiple questions.
marquee 9500ultra HD10L moome hdmi1.3 v3+ some mods.
|
|
Back to top |
|
|
RayN999
Joined: 25 May 2010 Posts: 207 Location: Minneapolis, MN
TV/Projector: Sony VPL-VW60 and Toshiba 65H84 CRT RPTV
|
Link Posted: Wed Aug 24, 2011 2:19 am Post subject: |
|
|
Sweet, thanks for the info. I've only recently rediscovered the vintage sound of vinyl, and I think it would be interesting to do a DIY 2 channel amp.
Been running a Grado Silver cartridge (Grado ZF1) on a cheapie Technics turntable that I got at a garage sale for $50 (including the Grado) through a Project phono preamp into a Marantz SR14EX receiver. This feeds a pair of Martin Logan Aerius i speakers that I got used from a high-end shop in Phoenix a couple of years back.
Sitting in the sweet spot, with some new vinyl from Music Direct, makes for some very enjoyable listening....
Now if this amp can drive the MLs, that might be the last piece of the puzzle that I'm looking for. The receiver is capable of 7.1 decoding, but has only 5 amp channels & has pre-out for 7 channels, amp in for 5. So I can use the onboard for the center, side, rears & use this tube amp to drive the mains (and maybe a mono-derived version for the center channel, also a ML, Cinema speaker).
That amp looks to have a nice clean minimalist design in the output stages, still reviewing the other stages.
Thanks so much for sharing, I appreciate the info from another DIYer.
Ray
_________________ Ray Nelson
N9QBV
|
|
Back to top |
|
|
dvh99
Joined: 25 Dec 2009 Posts: 2158 Location: nederland
|
Link Posted: Wed Aug 24, 2011 2:56 am Post subject: |
|
|
yes this amp can drive a martin logan, i am sure.
you could opt for bigger toroids if you think this is needed.
i used 300va per channel plus a 70va for the aikido stage.... and a small transformer for 2 softstarts .
if you like a lot of headroom go for 500va per channel or more but be sure to use a softstart circuit for those big toroids.
i also used screw type ps caps, i got these on ebay and they are fantastic, my voltage is at 29.72vdc on both channels, not a mv the difference.
i used a rcrcrcrcc configuration.
8*4700uf and 2*14000uf.
the 4700 measure 5200uf so that is about 70.000uf per channel and that really is enough when using screw type caps.
http://www.farnell.com/datasheets/526225.pdf
http://www.vishay.com/docs/42065/36dy.pdf
i used a big piece of solid copper to connect the ps caps, this way you have a nice signal ground too.
bob prangell compared this amp to a f4 pass labs and it was simply no match he said.
if you like vinyl get the phono pre from john broskie too and a line stage pre and maybe a step up transformer when using a low output mc cartridge, this will be far better then using the pre out from a reveiver, the aikido design is quite unique and so is its sound.
it`s on par with a kraudio transducer amp and that says a lot.
last thing, the schematic says to use hexfred bridges but a regular rectifier bridge works quite well i can assure you.
_________________ 1 answer always poses multiple questions.
marquee 9500ultra HD10L moome hdmi1.3 v3+ some mods.
|
|
Back to top |
|
|
dvh99
Joined: 25 Dec 2009 Posts: 2158 Location: nederland
|
Link Posted: Wed Aug 24, 2011 3:11 am Post subject: |
|
|
this amp will cost you 1000usd at least when using quality components.
if i were to rebuild this amp i would use a heatsink like this so i could bias the fets a little higher. (currently 185mv across the source resistors)
http://nl.farnell.com/fischer-elektronik/la-17-200-24v/heat-sink-fan-cooled-24v/dp/1222532
for the source resistors i used 5*1ohm/1watt thick film smd resistors in parallel.
this is every bit as good as an expensive caddock resistor but much cheaper.
_________________ 1 answer always poses multiple questions.
marquee 9500ultra HD10L moome hdmi1.3 v3+ some mods.
|
|
Back to top |
|
|
|
|