Testing my amp
As can be seen from picture i use a 42+42V smps and Dynaudio Focus 160 speakers. After few hours of listening i can say the amps sounds nice. First thing noticed is the large soundstage and a little bit emphasis on treble wich i think is from my SMPS or maybe the amp needs to settle a litlle after few tens of hours.Bass is nice, a little puncy wich i like.This amp will definetly go to a nice Modushop case but my DIy time is very limited in the last months and will take more time.
Beeing very revealing on audio material i hope to sound good also with my vinyl player as i tested only with digital.
What do you think Shaan, the amp will change its sound after few tens of hours of usage?
An externally hosted image should be here but it was not working when we last tested it.
As can be seen from picture i use a 42+42V smps and Dynaudio Focus 160 speakers. After few hours of listening i can say the amps sounds nice. First thing noticed is the large soundstage and a little bit emphasis on treble wich i think is from my SMPS or maybe the amp needs to settle a litlle after few tens of hours.Bass is nice, a little puncy wich i like.This amp will definetly go to a nice Modushop case but my DIy time is very limited in the last months and will take more time.
Beeing very revealing on audio material i hope to sound good also with my vinyl player as i tested only with digital.
What do you think Shaan, the amp will change its sound after few tens of hours of usage?
Last edited:
Hi Adrian!
Great to know you got them running.
This amp has a very high HF response and also a fast slew rate and doesn't sweat for a 10 or 20KHz signal. I haven't noticed it having a focus in treble neither a change of sonics after a few hours of playback. However, this is only my case. We all listen differently and our speakers and listening environments are different, so it is very much possible that the sonics might change after it has been running for some time. There is also what they call "forming" of electrolytic capacitors which, if true, can influence the sound after the caps have settled internally, particularly the 2200uF capacitors. So I won't say expect no change.
I have been reported by some owners of V4 that for some speakers Class-A operation brings it to life. An owner called its revealing production "porn level"!
In one very interesting case the the amplifier sounded dull through the speakers. Turned out the speakers didn't like control over the cone. The owner put a 1 ohm resistor in series with the output, and as he reports it is singing beautifully now. Lots of experiments can be done to tune its sound to your taste although it seems the amp's sonics are already in your comfort zone.
Thanks for sharing your thoughts. Do share more.
Last edited:
Jumpers and input plug advice
I'm trying to find the 'input" header and plug connector as well as the shorting header, but neither are not listed in the BOM that I could find. Can you provide a link to one, or provide the spacing?
Also I already have these breakaway header pins, but they are round. Can you recommend a good housing to short them and for the input plug?
Break Away Headers - Machine Pin - PRT-00117 - SparkFun Electronics
I'm trying to find the 'input" header and plug connector as well as the shorting header, but neither are not listed in the BOM that I could find. Can you provide a link to one, or provide the spacing?
Also I already have these breakaway header pins, but they are round. Can you recommend a good housing to short them and for the input plug?
Break Away Headers - Machine Pin - PRT-00117 - SparkFun Electronics
Input connector:
Jumper Wire - 0.1", 3-pin, 6" (Black, Red, White) - PRT-13164 - SparkFun Electronics
You can use one of these for two channels. Cut the strap in the middle. Remove the middle red wire and you'll get two female headers with 0.2" pitch. Twist the wire pair and use white for + and black for -.
Jumper shunt:
Jumper - 2 Pin - PRT-09044 - SparkFun Electronics
These should work on round pins as long as the pitch is 0.1".
quick question, whats power of chasis do you run your peeceebee with?
I got some nominal 60 W speakers attached to it right now, 4 Ohms that is, nominal input voltage PCB equals +- 33V
And I gotta say my cooling mount is big, but it gets fairly hot, barely touchable so I would say around 60°C at least, for what was that Peeceebee originally designed?
You obviously cannot run some normal hifi living room speakers with it, I would say, maybe I am wrong? Something is wrong with my bias currents, I normally work with my setup around half an hour, then I switched it off, I am afraid something will go up in flames
I will post some pics, when I get to it.
Thanks.
I got some nominal 60 W speakers attached to it right now, 4 Ohms that is, nominal input voltage PCB equals +- 33V
And I gotta say my cooling mount is big, but it gets fairly hot, barely touchable so I would say around 60°C at least, for what was that Peeceebee originally designed?
You obviously cannot run some normal hifi living room speakers with it, I would say, maybe I am wrong? Something is wrong with my bias currents, I normally work with my setup around half an hour, then I switched it off, I am afraid something will go up in flames
I will post some pics, when I get to it.
Thanks.
Yes it is on. We are less than minimum total PCB entries. But will send invoices to all GB3 members tonight.
Thanks.
quick question, whats power of chasis do you run your peeceebee with?
I got some nominal 60 W speakers attached to it right now, 4 Ohms that is, nominal input voltage PCB equals +- 33V
And I gotta say my cooling mount is big, but it gets fairly hot, barely touchable so I would say around 60°C at least, for what was that Peeceebee originally designed?
You obviously cannot run some normal hifi living room speakers with it, I would say, maybe I am wrong? Something is wrong with my bias currents, I normally work with my setup around half an hour, then I switched it off, I am afraid something will go up in flames
I will post some pics, when I get to it.
Thanks.
It was designed for any bias you want (upto 2A or so). VR3 was added for that. I have run it in blazing hot Class-A mode with 120W quiescent dissipation and although the heatsinks were huge it still needed forced airflow, for instance.
In 4R speakers the amplifier will produce 90W maximum unclipped power (and will produce around 60W of heat by itself). If the heatsink is getting hot as you describe without signal and with 100mA bias then among many reasons the first suspects are the heatsink being not adequately sized, or horizontal or upside down fin orientation resulting in poor air convection, or enclosed heatsink with less than optimal ambient cooling.