Which is the latest revision/version of SymAsym? I want to build 2 mono-blocks and am considering SymAsym. Of course I would like to use the latest revision as a starting point. From what I googled, it should be 5.4? Is this one available for download anywhere (schematics/PCB), preferably for KiCAD?
You are right, they should. Few do.
It's a tradeoff, cost vs service. Many of the sellers give extremely low price and almost no support. No schematic, no BOM. I've asked. You have to reverse engineer it from what you buy.
I copied this purported schematic from another vendor's offering. No guarantee it matches product.
Attachments
Oh, yes. I ended up buying the pcbs elsewhere, where they put all the info you need:
Symasym5-3 X2 discrete element power amplifier board space board classical discrete element power amplifier board
Very little differences, except for adding one more pair of output transistors and using +/- 45v. I should use a regulator tor the low current stages.
I would like to try enclosed pairs for the LTP, but I would have to add a cascode due to voltage limits.
Has anyone tried a DC servo, with good or bad results?
Symasym5-3 X2 discrete element power amplifier board space board classical discrete element power amplifier board
Very little differences, except for adding one more pair of output transistors and using +/- 45v. I should use a regulator tor the low current stages.
I would like to try enclosed pairs for the LTP, but I would have to add a cascode due to voltage limits.
Has anyone tried a DC servo, with good or bad results?
Each vendor has different policy on schematics. I see two offerings at Jim's, one for 2 bare boards with onboard fuses, the second for one assembled amp on a different board with no fuses. With the puchase, Jim's says they will email the actual schematic and with the bare board BOM too. I bought 2 bare boards.
Here are the Jim's ebay listings as of today. You may have to search if these closed.
150W Class AB Power Amplifier PCB Based on SYMASYM5 3 | eBay
150W Class AB Power Amplifier Assembled Based on SYMASYM5 3 | eBay
Hi I am going to build the Symasym 5_3. I have a nice case and a very good twin power supply already. The hitch is the supply rails are +-43.5 volts. Can anybody tell me if this a major problem ? Could somebody kindly advise as to what I need to change / swop to handle the higher rail voltage ?
Hi Simon,
I think design center was for 35 volts. Just look at your parts and substitute any that won't handle the 97 volts they will see. 100 volt parts are cutting it too close, so you might want to look at 120 volt parts as a minimum. If the diff pair is cascoded, you can get away with much lower voltage parts.
It wouldn't hurt to look at the power dissipation for some parts also.
-Chris
I think design center was for 35 volts. Just look at your parts and substitute any that won't handle the 97 volts they will see. 100 volt parts are cutting it too close, so you might want to look at 120 volt parts as a minimum. If the diff pair is cascoded, you can get away with much lower voltage parts.
It wouldn't hurt to look at the power dissipation for some parts also.
-Chris
Hi,
I would like made a simple symasym version with 2SK170BL (8mA) input, but with lateral mosfet output and 25VAC transformer
Someone could help me for the schematic ?
https://sites.google.com/site/opampbasedamp/SYM_LAT.asc
https://sites.google.com/site/opampbasedamp/TELOS_L.asc
thanks
I would like made a simple symasym version with 2SK170BL (8mA) input, but with lateral mosfet output and 25VAC transformer
Someone could help me for the schematic ?
https://sites.google.com/site/opampbasedamp/SYM_LAT.asc
https://sites.google.com/site/opampbasedamp/TELOS_L.asc
thanks
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You want someone to design and test a new amplifier for you
How much are you willing to pay?!
I am not sure why you want to change anything ? I built version 5.3 2 weeks ago, and yes this is a seriously nice amplifier. Works very well in my system, just love listening to the music and yes this design is very musical ! Great grip and resolution of lower chords, clear mids and highs. But what sets it apart is that it does this so well whilst keeping you involved with the rhythm of the music.
I did use a twin +-42Volt power supply and had to swop the MPSA18's for 2N5551 and the BC546 for 2N5401. That said I guess it shows going to higher rail volts is not a problem. Anyway I highly recommend the amplifier easy & relatively cheap to make also.
I did use a twin +-42Volt power supply and had to swop the MPSA18's for 2N5551 and the BC546 for 2N5401. That said I guess it shows going to higher rail volts is not a problem. Anyway I highly recommend the amplifier easy & relatively cheap to make also.
Attachments
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yikes!
that latfet2.pdf looks a little dicey with 2sk170 using 32v rails with no cascode.
mlloyd1
that latfet2.pdf looks a little dicey with 2sk170 using 32v rails with no cascode.
mlloyd1
Hi caglarm,
Now we see the picture of what we assume is the schematic you posted. It is "very dicey" indeed. So, do you have a layout, or was this just wired out on some kind of basic "amplifier PCB"?
Working very well means that it sounds good to you. Were you able to take any measurements for distortion and power output at various frequencies? I'm not putting your amplifier down, just trying to quantify what you have there. I think it's great that you were able to simulate a circuit, and then build it and it worked as it simulated.
-Chris
Now we see the picture of what we assume is the schematic you posted. It is "very dicey" indeed. So, do you have a layout, or was this just wired out on some kind of basic "amplifier PCB"?
Working very well means that it sounds good to you. Were you able to take any measurements for distortion and power output at various frequencies? I'm not putting your amplifier down, just trying to quantify what you have there. I think it's great that you were able to simulate a circuit, and then build it and it worked as it simulated.
-Chris