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Russ White said:Jason, your voltage drops seem a bit high, but I suspect that even if they were normal your preamp would have issues. For one thing the power resistors absolutely need to be raised above the PCB. Did you notice the little notes on the PCB? "Raise R1(R2) and R6(R7) 1/2" above the PCB."When the power resistors get too hot they increase in resistance which will increase the voltage drop accross them.
Also a note, This kit was never intended for absolute beginners, people who are not comfortable with projects like this simply should not attempt the project. Also this is not a commercial endeavor, but a community driven DIY project. Brian and I are always glad to help be we don't expect to be the sole providers of building instructions. This is not a "product" but rather a community "project". The PCB is straight forward and the parts well labeled. If you need help beyond that you should post.
For those with questions, it is only natural so please don't hesitate to post if you can't find an answer. And post early, before you make a critical mistake. If you are in over your head, stop, ask, understand, and then continue.
Now that said, a manual is planned(and actually a lot of the prep done), but Brian and I have real jobs to do outside of DIY audio, so don't expect it to happen immediately.
Cheers!
Russ
The manual was not for me
some one emailed me asking if i had it and i said no i don't.I'll raise the resistors off the board and see what happens. Is there any thing else i should check. All the zeners test fine. All resistors test fine. All fets test fine also.
Jase
Banned
Joined 2002
Sorry, responded too quickly. One more caution. The circuit as wired does not provide a drain to the big caps on the amplifier board. They can sit a high voltages for some time (hours) as I found the hard way. I found I had to be real careful applying voltage, measuring, and then checking components.
There is not much else in the path of R3 that could be allowing it such a high voltage if the components are good. The simple answer that I hope you won't take the wrong way, is that the voltage across R3 would be what you get on the good board. There are enough variations in setup, power supply zeners and transformers, that there isn't a much better answer without really looking at your components more closely.
There is not much else in the path of R3 that could be allowing it such a high voltage if the components are good. The simple answer that I hope you won't take the wrong way, is that the voltage across R3 would be what you get on the good board. There are enough variations in setup, power supply zeners and transformers, that there isn't a much better answer without really looking at your components more closely.
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Joined 2002
Well you can look at these pictures > http://jleaman.ath.cx/bos/
The transformers are the same ones that Russ uses.
Maybe ill raise the resistors and see how hot they really get hoping they donw smoke to bad etc etc.
My other idea was to ask Metal Man to send my pre-amp to him since he is just across the water
What you think Metalman ?
The transformers are the same ones that Russ uses.
Maybe ill raise the resistors and see how hot they really get hoping they donw smoke to bad etc etc.
My other idea was to ask Metal Man to send my pre-amp to him since he is just across the water
What you think Metalman ?
eapavant said:
You are certainly welcome. And thank you all for your support and encouragment. So many of you guys have made this a really incredible hobby for me.
Regarding the DAC I went back to the drawing board and am now going to use a Wolfson chip. I will post more details on that thread.
The SuSy amp is neary complete, just waiting for a couple parts. It and the Balanced DAC along with XBOSOZ will be a complete system.
Thanks for the interest, it helps keep me going.
Cheers!
Russ
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Joined 2002
Russ White said:
You are certainly welcome. And thank you all for your support and encouragment. So many of you guys have made this a really incredible hobby for me.
Regarding the DAC I went back to the drawing board and am now going to use a Wolfson chip. I will post more details on that thread.
The SuSy amp is neary complete, just waiting for a couple parts. It and the Balanced DAC along with XBOSOZ will be a complete system.
Thanks for the interest, it helps keep me going.
Cheers!
Russ
I thank you for your efforts too. Good job on every thing. Please keep up the good work.
Russ White said:
You are certainly welcome. And thank you all for your support and encouragment. So many of you guys have made this a really incredible hobby for me.
Regarding the DAC I went back to the drawing board and am now going to use a Wolfson chip. I will post more details on that thread.
The SuSy amp is neary complete, just waiting for a couple parts. It and the Balanced DAC along with XBOSOZ will be a complete system.
Thanks for the interest, it helps keep me going.
Cheers!
Russ
Cool, so the SuSy as a kit is almost done? I can't wait. I am trying to get one working now but it is giving me grief with dc. I will check your dac thread. Thanks!
Banned
Joined 2002
Jason, sorry for the delayed response. I was out of town on business the last several days. I sent you a pm with my private contact info back a few days via diyaudio. Did you get it?
I have a couple more thoughts to try before I think it is worthwhile spending on shipping costs. However, if it comes to that I don't mind taking a shot at troubleshooting it for you.
Cheers,
Terry
Banned
Joined 2002
Banned
Joined 2002
PROGRESSS!!
Well we have lift off I only powered one channel up at a time ONE works one does not. They both produce sound but the other one is really faint. I think it is the zener dodes i checked them again and they are really dead now.
I have to admit at half there voltage using a variac them resistors get hot still.I think im going to order some 5 watt ones or get the same ones Russ uses from Digi Key
For the 10 min of listening to the good chanel im impress with clean sound..
Rca in Balanced out
Well we have lift off
I only powered one channel up at a time ONE works one does not. They both produce sound but the other one is really faint. I think it is the zener dodes i checked them again and they are really dead now. I have to admit at half there voltage using a variac them resistors get hot still.I think im going to order some 5 watt ones or get the same ones Russ uses from Digi Key
For the 10 min of listening to the good chanel im impress with clean sound..
Rca in Balanced out
Banned
Joined 2002
Banned
Joined 2002
Here are some pic's of the pre-amp in action. The fix for this. checked the diodes & replaced the thin isolation pad's. If any one wants the part # for the pads that i have used please just email me.
More images @ http://jleaman.ath.cx/bos/
More images @ http://jleaman.ath.cx/bos/
Attachments
I have a question for Russ or anyone else that might know. My XBOSOZ is up and running with no problems. I have zero vdc on the output of one channel and +.02 vdc on the other. I just finished my joshua tree attenuator and have it hooked up on the input side. When I connect the preamp to my chip amp I get spikes close to 3vdc on the outputs of the power amp. This only happens when the the two are connected. I do not usualy get dc at the outputs of the power amp with my kookaburra and the same cd player. Any ideas?
Hi,
Well I am very surpised you have any DC at all out of the XBOSOZ, the Output caps should not allow any. Not sure where to look there.
One word of advice, the XBOSOZ will sound better with the attenuator on output.
EDIT: One thing I would do is double check the soldering on the JT, you may have a relay power trace bridged to a signal trace. Go over it with your DMM to be sure the relay power pins and the signal pins are completely isolated. I know the joshua tree is a tight layout and it would be easy to have a solder bridge.
Cheers!
Russ
Well I am very surpised you have any DC at all out of the XBOSOZ, the Output caps should not allow any. Not sure where to look there.
One word of advice, the XBOSOZ will sound better with the attenuator on output.
EDIT: One thing I would do is double check the soldering on the JT, you may have a relay power trace bridged to a signal trace. Go over it with your DMM to be sure the relay power pins and the signal pins are completely isolated. I know the joshua tree is a tight layout and it would be easy to have a solder bridge.
Cheers!
Russ