Negative rail in output
folks, Can you please help me out here. This is my second diy project and struggling to get this to work. I am using the silicon ray 2005 jlh board with their PSU, i am measuring negative 26 volts on my output.
I am using MJ15003 for output, BD139/140 and BC560
replaced all the transistors one full round with no results. Any help will be much appreciated.
folks, Can you please help me out here. This is my second diy project and struggling to get this to work. I am using the silicon ray 2005 jlh board with their PSU, i am measuring negative 26 volts on my output.
I am using MJ15003 for output, BD139/140 and BC560
replaced all the transistors one full round with no results. Any help will be much appreciated.
so you got full negative supply rail on the output? start with confirming thet the PSU is working. du you got +/-26V or there about?
he asks for help. but do not visit the tread for over 20 days after asking for help. that tells me he realy don't want help. so i'm out of it.
Hi,
so finally I've assembled my very first amplifier, and my very first JLH amplifier. After putting it all together in a chassis I've figured that the left channel is louder than the other. I assumed it could be corrected with VR2, but nothing changed.
As a background, I might have used some transistors from a different batch on the second board.
Is it possible to adjust the board from the VRs, or should I resolder all transistors to be from the same batch?
thanks
so finally I've assembled my very first amplifier, and my very first JLH amplifier. After putting it all together in a chassis I've figured that the left channel is louder than the other. I assumed it could be corrected with VR2, but nothing changed.
As a background, I might have used some transistors from a different batch on the second board.
Is it possible to adjust the board from the VRs, or should I resolder all transistors to be from the same batch?
thanks
Hi
I f you can measure HFE, match the transistors between left and right especially for the input transistor..
You can't adjust the unbalance with vr2.
Can you post the shema ?
I f you can measure HFE, match the transistors between left and right especially for the input transistor..
You can't adjust the unbalance with vr2.
Can you post the shema ?
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The gain is determined by the feedback network so I think the HFE of transistors won't affect it very much. I think haiduc32 should check the soldering first. For example, the fault soldering parts at the input stage will affect the loudness.
VR2 is used to adjust the 0 point, don't adjust it when it's balanced!
VR2 is used to adjust the 0 point, don't adjust it when it's balanced!
hi,
thanks for the replies, I don't have a DMM with HFE so no way to pair the transistors. I think I'll try to resolder the second board with transistors from same batch and see if that works out, but that'll be possible only in 2 weeks, I'll post back when I try.
thanks for the replies, I don't have a DMM with HFE so no way to pair the transistors. I think I'll try to resolder the second board with transistors from same batch and see if that works out, but that'll be possible only in 2 weeks, I'll post back when I try.
can you make a assembled power amp with case and supply included for this board ?
Marantz HDAM Design 200Wx2 Class A HiFi Amplifier SRH-02 - Boards | Kits | Components | Modules | Tools
Marantz HDAM Design 200Wx2 Class A HiFi Amplifier SRH-02 - Boards | Kits | Components | Modules | Tools
there's power supply here:
Free Power Supply PCB For JLH Amplifier - Boards | Kits | Components | Modules | Tools
RE3213H is suggested for this amp:
Enclosure RE3213H 320x130x311 - Boards | Kits | Components | Modules | Tools
Free Power Supply PCB For JLH Amplifier - Boards | Kits | Components | Modules | Tools
RE3213H is suggested for this amp:
Enclosure RE3213H 320x130x311 - Boards | Kits | Components | Modules | Tools
Oh sorry. the case could be custom made. Something like RE4821H could be used for it. 500W+ toroide transformer could be used as power supply. Shipping cost would be horrible
hi,
just wanted to drop by and say that I finally got my amp working. in my last post I said that one channel is louder than the other, after re-soldering some transistors and a new pair of capacitors nothing changed so I switched the channels and got the same results, conclusion: the pair of speakers that I used for tests were buggy. put it on my 8ohm tannoy and everything sounds wonderful.
here's a pic. thnx to to all who helped a noob like me get into diy audio.
just wanted to drop by and say that I finally got my amp working. in my last post I said that one channel is louder than the other, after re-soldering some transistors and a new pair of capacitors nothing changed so I switched the channels and got the same results, conclusion: the pair of speakers that I used for tests were buggy. put it on my 8ohm tannoy and everything sounds wonderful.
here's a pic. thnx to to all who helped a noob like me get into diy audio.
An externally hosted image should be here but it was not working when we last tested it.
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