Although I dont understand what you meant by above post, reply is best given by following two quotes (its actually what I meant in post # 10836)
1. "Chop your own wood and it will warm you twice" (signature by 44250)
2. "Give a man a fish and you feed him for a day; teach a man to fish and you feed him for a lifetime." again posted by 44250
Its helped me a lot in making PCB designs.
Also fawning (Calling Juan , "Juan Sir") isn't going to get you anywhere near your diy dreams
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Sorry that I have to come back again I already send a message to Sunny please don't ask me to check your work or any modification on any of design is up to you to do changes on your own I'm not a engineer I'm jusylike any diy member here that love to build your own stuff so please try to figure it out yourself I did that a few year ago and I thing I'm good now 
if I did it you too can achived
Best Regards
Juan
if I did it you too can achived Best Regards
Juan
yes they are, but I did not made them(this time I have only soldiered them)-i paid a man to do them for me. I believe they were made with photo sensitive film, I have seen many toner transfer made pcb's from wich most were really good made - but this is just one step further in precision.
Mile, is it safe to decrease amplifying ratio to 1? I wish to put 22k instead 10k at input, and switch with 18k resistor in parallel to achieve two amplifying ratios: 1 and 2,2. would it oscillate?
Use input OP as buffer if you don't need gain like in first version of this preamp or use this circuit.
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yes. i made a mistake at MM-MC phono preamplifier,so later i will post corrected files. i have also decreased current of a-class shunt to achive less heating in inclosure by increasing 22r to 47r (for pair of phono) and to 62r (for preamp with tone controle). i have put 22k at input of preaplifier with tone controle and a switch with 18k in parallel with that 22k to achive amlifying ratio of 1 and 2,2. it is not necessary but that is what i wanted.
YouTube
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I have listened MM MC for a few hours now,and my first impressions are really good! I am not to experienced with phono theme, I had one phono preamp before this one. it was IC-based and it had (at my opinion) too much amplifying and it bursted a bit at high frequencies. MM MC does its job much more natural and pretty equally at all frequencies, from bass to treble. i think it should have a bigger amplifying ratio but it is quite enough as it is,all in all. for sure,it is a step further than I was until now.
Preamp with tone controles works also really nice,and whole system is really quiet even with everything on max and with MM MC as a signal source. quite pleasantly surprised!
Preamp with tone controles works also really nice,and whole system is really quiet even with everything on max and with MM MC as a signal source. quite pleasantly surprised!
Hello friends. I want to build the HX-11 class H but I would like to make some changes such as adding a pair of transistors more per rail (total six transistors) to make use of a big transformer that I got from an amplifier. I think one of the changes I have to make is replace the diodes that pass +/-VL. The power supply provides +/-35V, +/-75V. Any suggestion, I would thank you.
have you resolved problem? I have had problem with bias stability but oscilloscope had not showed me such problems... i do not know what would be a problem in your case, but it seems it is in "positive" side of power amplifying, I would start by checking that side of an amplifier board. compensations on that side,transistors pinout, value of resistors at their place... i have had problems with different markings of capacitors, so instead of (in my that one case) 330pF I have installed 33pF. manufacturer of capacitors I have had in that moment marks capacitors in a different way than others, and I have bought them as 330pF. naturally, amplifier had "seen" that and it was not glad,so it had oscillated.
Guys, I still fighting with one channel of my Apex A40.. I am able to set bias,offset, but when i increase voltage over +-9V signal looking very strange...
Amplifier is unstable and breaking into oscillation.
Increase C9/10.
R21/22 can affect oscillation too, I usually use 10R in those positions.
