if your amp has a gain of +26dB and a signal to noise ratio of 115dB then the noise and hum at the input must be 141dB below the maximum output level.
60W into 8r0 is equivalent to ~22Vac.
-141dB ref 22Vac is ~2uVac.
If the noise and/or hum/buzz at the Signal Ground is near or above 2uVac, then your amplifier output will be degraded.
If your Signal Ground is referenced to that muckle great copper plate on the smoothing caps then you are guaranteed that you have >2uVac of noise on your Signal Ground.
You must move your Audio Ground off the dirty ground that is the zero volts power plate.
Yes, but where to?!
I realized, if you refer back to the images I previously attached, I can combine all grounds on the same bolt. are you suggesting taking all ground connections to a separate position and connect the capacitors to it as well by a wire?
also I noticed that when the input buffer PS is connected, many 50Hz harmonics are appearing on the spectrum, highest at
I also notice that when 1KHz tone is played on the input, a 80dB 2K harmonic is also apparent. is that normal (I suspect not)? what can cause that? it does not appear on the input buffer's output. I'm running at 13Vac RMS according to the DMM and measuring on a resistor that sees one seventh of the signal.
Hi,
let all the dirty rectified voltages/currents circulate across that copper plate and back to the transformer via the rectifiers. Keep these wires short and twisted as pairs.
Take one wire from the copper plate. At the end of this short wire attach a solder tag and a brass set screw. Attach all your other grounds to this set screw using solder tags. This set of solder tags is your Audio Ground. Locate it such that as many wires to the various circuit boards and terminals are as short as possible. Put on a nut and tighten.
Swap around the order of the various solder tags to minimise the artefacts appearing on the output. Yes, the order does make a difference. Basically place the cleanest/lowest current grounds towards one end of the stack of tags and the dirtiest/highest current grounds towards the other end of the stack.
let all the dirty rectified voltages/currents circulate across that copper plate and back to the transformer via the rectifiers. Keep these wires short and twisted as pairs.
Take one wire from the copper plate. At the end of this short wire attach a solder tag and a brass set screw. Attach all your other grounds to this set screw using solder tags. This set of solder tags is your Audio Ground. Locate it such that as many wires to the various circuit boards and terminals are as short as possible. Put on a nut and tighten.
Swap around the order of the various solder tags to minimise the artefacts appearing on the output. Yes, the order does make a difference. Basically place the cleanest/lowest current grounds towards one end of the stack of tags and the dirtiest/highest current grounds towards the other end of the stack.
If anybody is interested I am selling my BPA 300 stuff.
It is boards AND parts for 2 channels + the DRV134 driver.
I haven't received as yet but I have been informed that almost all the parts are there.
I will sell for what it cost me + any paypal charges if applicable.
contact me offline if interested.
thx,
L
It is boards AND parts for 2 channels + the DRV134 driver.
I haven't received as yet but I have been informed that almost all the parts are there.
I will sell for what it cost me + any paypal charges if applicable.
contact me offline if interested.
thx,
L
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Wanted to buy...BPA300
I am interested in buying all of the PCBs required to put together the amp I have seen at Shine7. I once paid a fair amount of cash to an individual who claims to have had the parts. To this day I have not received the PCBs (BPA300 and DRV134). I have been given the runaround for months now, several promises to repay. The guy actually never even confirmed that he ever tried to send them. I think it was a scam from the beginning.
I have thought long and hard about releasing all of his information here so nobody else will get burned by this guy. Anyway, at this point I have decided to keep him anonymous as he is still promising to repay me.
Still, that leaves me without the parts I set out to acquire about 5 months ago. Can anybody here help me to get these PCBs?
I saw a group buy above but I am unfamiliar with the SEK, can anybody tell me in USD what these cost for the entire set to build a stereo set up? Also if the group buy is still going on and if I can get in?
Thanks for your help,
Jeff M.
I am interested in buying all of the PCBs required to put together the amp I have seen at Shine7. I once paid a fair amount of cash to an individual who claims to have had the parts. To this day I have not received the PCBs (BPA300 and DRV134). I have been given the runaround for months now, several promises to repay. The guy actually never even confirmed that he ever tried to send them. I think it was a scam from the beginning.
I have thought long and hard about releasing all of his information here so nobody else will get burned by this guy. Anyway, at this point I have decided to keep him anonymous as he is still promising to repay me.
Still, that leaves me without the parts I set out to acquire about 5 months ago. Can anybody here help me to get these PCBs?
I saw a group buy above but I am unfamiliar with the SEK, can anybody tell me in USD what these cost for the entire set to build a stereo set up? Also if the group buy is still going on and if I can get in?
Thanks for your help,
Jeff M.
You should have come forward much sooner but you should go to Paypal and claim a refund. You can read my blog to get more info.
Exchange rates
Exchange Rates Table for Swedish Krona, Sweden
You can sign up for PA150 pcb's etc. Check my sig below.
I'll send you a Paypal invoice in SEK and you just pay me in SEK (since Paypal has this currency). You don't have to worry about any exchange rates.
Exchange rates
Exchange Rates Table for Swedish Krona, Sweden
You can sign up for PA150 pcb's etc. Check my sig below.
I'll send you a Paypal invoice in SEK and you just pay me in SEK (since Paypal has this currency). You don't have to worry about any exchange rates.
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Well, lets put it this way....I had to threaten him with putting all of his information on the forums, including his personal phone number, to get him to respond back to me. You are right though I should have done both earlier on but I did not have the time nor the worry over $65 when this was going on 5 months ago.
Sure, I could pay in SEK through Paypal but I would like to know first how much they are in USD.
Jeff
Sure, I could pay in SEK through Paypal but I would like to know first how much they are in USD.
Jeff
You´re da man
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