Hi Everyone
Here is my nxV200 Amplifier I just completed.
I used a www.designbuildlisten.com 60mm chassis with some Conrad MF30-50 heat sinks.
The input and output connectors are ETI Phono Pods, ETI Cable Pods and Neutrik Powercon mains socket.
Here is my nxV200 Amplifier I just completed.
I used a www.designbuildlisten.com 60mm chassis with some Conrad MF30-50 heat sinks.
The input and output connectors are ETI Phono Pods, ETI Cable Pods and Neutrik Powercon mains socket.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
I built a ESP project P03A amp some 2 years ago.
I've gone for a powerhouse for a smallish PA system, and built 2 boards (4 channels) in one box.
The chassis is from an old computer disk drive (DEC SCSI drives for MicroVax computer) that I salvaged from the company I work for.
I've used MJE15004/4 as output transistors, and each board (2 channel) has it's own PSU (30-0-30V 5A)
The heatsink I imported from Australia as it was exactly the size required for the chassis, and there are 2 12V fans blowing onto the heatsink. The fans are powered by the 12V supply that was in the chassis to power the disk drives.
I'm no eletronics fundi, and in fact know very little, but I domknow enough to be able to read a schematic diagram, and follow instructions...
This amp is used from time to time, and has never let me down, and is as quiet as I never imagined it could be.
I am planning on installing a soft start circuit very soon.
I've fitted XLR inuts and SpeakOn sockets for output conectors.
This has been my first that I built from scratch. Some shots of "The Beast" as it's got quite a weight with those two torroidals in there!
I've gone for a powerhouse for a smallish PA system, and built 2 boards (4 channels) in one box.
The chassis is from an old computer disk drive (DEC SCSI drives for MicroVax computer) that I salvaged from the company I work for.
I've used MJE15004/4 as output transistors, and each board (2 channel) has it's own PSU (30-0-30V 5A)
The heatsink I imported from Australia as it was exactly the size required for the chassis, and there are 2 12V fans blowing onto the heatsink. The fans are powered by the 12V supply that was in the chassis to power the disk drives.
I'm no eletronics fundi, and in fact know very little, but I domknow enough to be able to read a schematic diagram, and follow instructions...
This amp is used from time to time, and has never let me down, and is as quiet as I never imagined it could be.
I am planning on installing a soft start circuit very soon.
I've fitted XLR inuts and SpeakOn sockets for output conectors.
This has been my first that I built from scratch. Some shots of "The Beast" as it's got quite a weight with those two torroidals in there!
Attachments
In conclusion, I want to thank the guys on this site for their insight and ability and willingness to share expert knowledge.
By lurking here for the last month, I've learned so much!
In parting: The business end of any amplifier: The PSU transformer:
30-0-30v 5A ordered from RS Components in South Africa.
By lurking here for the last month, I've learned so much!
In parting: The business end of any amplifier: The PSU transformer:
30-0-30v 5A ordered from RS Components in South Africa.
Attachments
what spec is this amp???
hi i just got this ampilifer it called radiovox leeds. It very very heavy all solid metal like it's built like a tank. The transisters are outside on the heatsink of the amp. It looks like some retro bbc amp. does anyone know what spec this be thier no information on this amp. i will be posting image soon.
hi i just got this ampilifer it called radiovox leeds. It very very heavy all solid metal like it's built like a tank. The transisters are outside on the heatsink of the amp. It looks like some retro bbc amp. does anyone know what spec this be thier no information on this amp. i will be posting image soon.
Yap
The new YAP (Yet Another Poweramp) output stage.
A fully symmetrical, current feedback design:
- 3 x 2SK1530/2SJ201 outputs
- diamond buffers
- so-called Hawksford cascode gain stage
- current feedback input stage
- an original, quite simple, and according to my measurements totally transparent output devices overcurrent/output short protection circuit.
Preliminary results (most of them measured):
- 150W in 8ohm, 300W in 4ohm, 480W in 2ohm (short term) at +/-56V. At over 480W in 2 ohm the overcurrent protection (set to about 22A) kicks in an shuts down the output.
- Closed loop gain = +1
- 8MHz unity loop gain
- 85 degree phase margin
- 0.005 degree closed loop phase shift
- Non-slewing with intrinsic SR=350 V/uS (before Zoebel)
- Stable with 2uF capacitive load
- Works fine without output coil in any speaker emulation load I was able to provide and test. 0.6uH damped by 4.7 ohm included on board "just in case".
- THD20:
-> 0.002% (-94dB) @ 150W into 8ohm
-> 0.003% (-90dB) @ 300W into 4ohm
-> 0.01% (-80dB) @ 480W into 2 ohm
- 19+20KHz IMD:
-> 0.002% (-94dB) @ 150W into 8ohm
-> 0.003% (-88dB) @ 300W into 4ohm
-> 0.01% (-77dB) @ 480W into 2 ohm
Finishing measurements and laying out the final PCB for the front end/gain stage (high speed opamp based). Everything (schematics, Gerbers, measurements, etc...) will be available on my web site as soon as I'll find some time to create the web content.
The new YAP (Yet Another Poweramp) output stage.
A fully symmetrical, current feedback design:
- 3 x 2SK1530/2SJ201 outputs
- diamond buffers
- so-called Hawksford cascode gain stage
- current feedback input stage
- an original, quite simple, and according to my measurements totally transparent output devices overcurrent/output short protection circuit.
Preliminary results (most of them measured):
- 150W in 8ohm, 300W in 4ohm, 480W in 2ohm (short term) at +/-56V. At over 480W in 2 ohm the overcurrent protection (set to about 22A) kicks in an shuts down the output.
- Closed loop gain = +1
- 8MHz unity loop gain
- 85 degree phase margin
- 0.005 degree closed loop phase shift
- Non-slewing with intrinsic SR=350 V/uS (before Zoebel)
- Stable with 2uF capacitive load
- Works fine without output coil in any speaker emulation load I was able to provide and test. 0.6uH damped by 4.7 ohm included on board "just in case".
- THD20:
-> 0.002% (-94dB) @ 150W into 8ohm
-> 0.003% (-90dB) @ 300W into 4ohm
-> 0.01% (-80dB) @ 480W into 2 ohm
- 19+20KHz IMD:
-> 0.002% (-94dB) @ 150W into 8ohm
-> 0.003% (-88dB) @ 300W into 4ohm
-> 0.01% (-77dB) @ 480W into 2 ohm
Finishing measurements and laying out the final PCB for the front end/gain stage (high speed opamp based). Everything (schematics, Gerbers, measurements, etc...) will be available on my web site as soon as I'll find some time to create the web content.
jam said:
Don't know for sure yet, but it looks like it will be a very close race
The big improvements are the complexity, size and cost, all at less than 50% (comparing to the PGP amp). The front end fits easily in the space remaining on the right size of the heatsink (although I am not sure if i'll place it there, for thermal reasons). That's about it, from a signal path perspective.
One can add whatever front end it pleases, even a LM4702 or LME49810 driver works great (although, performance wise, it's not the best choice).
Very Great amplifier, syn08
Two things I like especially:
1. The use of Lateral type 2SK1530/2SJ201
They are not too often used. Unfortunately. They are powerful.
Because when using them we might not need to parallel so many 2SK1058/2SJ162.
2. Symmetrical and 'current feedback' to input.
Those that have noticed my lately posted amplifiers topologies
may have seen that this is what I am now into.
Most often using 'Complementary' N-JFET+P-JFET input stage
with feedback to the common Sources node.
thanks for your image
your circuit look just great, to me