@ mbrennwa
Look post 105 of this thread : Zen Mod share a 30v variation
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2sk170bl received today. I remove the j111 and put them instead ...
Every things is OK now .... Q1 drain set to 11.50V (VCC 23.0V). Tested with fountek fe85 in iBIB enclosure : the sound is really intesresting. Now I can start the O2.
Conclusion : j111 is not a remplacement for 2sk170 in this build ...
Thanks again to every for the help (and Mr Pass for this design)
Look post 105 of this thread : Zen Mod share a 30v variation
.2sk170bl received today
. I remove the j111 and put them instead ...Every things is OK now .... Q1 drain set to 11.50V (VCC 23.0V). Tested with fountek fe85 in iBIB enclosure : the sound is really intesresting. Now I can start the O2
.Conclusion : j111 is not a remplacement for 2sk170 in this build ...
Thanks again to every for the help (and Mr Pass for this design)
High supply voltage mods
I've got my supply cobbled together and I'm slightly above 28VDC with no load. It's a big transformer, so I don't think it will pull down too much. (no markings on the trafo reflecting power rating). In post 105 ZM suggested changes for 30VDC, so I thought those would probably work for me. I have a couple of questions.
1) It looks like I will have to cut a PCB trace to add the 2.2k resistor ZM suggests. I believe I see the place to cut on 'green' set of traces in the origianl article. What's the best way to do this?
2) It doesn't look like I need to use the LED as it will be cleaner for me to take it off the supply board in my planned layout. It it true that the LED and R13, for that matter are optional?
Thanks,
Skip
I've got my supply cobbled together and I'm slightly above 28VDC with no load. It's a big transformer, so I don't think it will pull down too much. (no markings on the trafo reflecting power rating). In post 105 ZM suggested changes for 30VDC, so I thought those would probably work for me. I have a couple of questions.
1) It looks like I will have to cut a PCB trace to add the 2.2k resistor ZM suggests. I believe I see the place to cut on 'green' set of traces in the origianl article. What's the best way to do this?
2) It doesn't look like I need to use the LED as it will be cleaner for me to take it off the supply board in my planned layout. It it true that the LED and R13, for that matter are optional?
Thanks,
Skip
Skip
I have built the ACA without the on board led and it works fine. I have used an Xacto knife to cut through the foil. I actually make two cuts about 1/16 inch apart and then pick out the small piece of trace to make sure there is no longer a connection. Don't know if that is the best way but it has always worked for me.
I have built the ACA without the on board led and it works fine. I have used an Xacto knife to cut through the foil. I actually make two cuts about 1/16 inch apart and then pick out the small piece of trace to make sure there is no longer a connection. Don't know if that is the best way but it has always worked for me.
naah
if you omit LED , it'll sound darker
I bet it would sound darker still if you use UV LED (we used to call them black lights in old days) haha.
That was funny ZM... You made me laugh.
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Having updated a pair of boards I had a pair left laying around. Dreamed up this to combine the mono blocks into a single chassis. This does require active (fans) cooling as these heat sinks aren't quite big enough.
That's cool
Finally Getting mine in a Chasis
Finally getting around to getting mine in a chassis.
I have another project going where I will be using point to point wiring, so I built a "standard" Pass Power Supply with a point to point approach and a 15V transformer.
Used tag strips and 600V wire to put the whole mess together. The .47R resistors are in a free form ladder. While not shown, I use the thermisitor/capacitor/thermistor as per the schematic. The caps are some from one of the last true surplus electronic stores in Houston.
This is the basic framework for the body, it too is a first go for another project. I will be building one of the other Pass Amps (M2) with the same chassis technique if this one works out.
Still Bench wiring, but have some good milspec/silver around for the real job
It's been a fun project
Finally getting around to getting mine in a chassis.
I have another project going where I will be using point to point wiring, so I built a "standard" Pass Power Supply with a point to point approach and a 15V transformer.
Used tag strips and 600V wire to put the whole mess together. The .47R resistors are in a free form ladder. While not shown, I use the thermisitor/capacitor/thermistor as per the schematic. The caps are some from one of the last true surplus electronic stores in Houston.
This is the basic framework for the body, it too is a first go for another project. I will be building one of the other Pass Amps (M2) with the same chassis technique if this one works out.
Still Bench wiring, but have some good milspec/silver around for the real job
It's been a fun project
Yes, they are. Don't ask if they are hooked up - to anything! Thought it would be fun to just drop a couple in the holes.
Final version: Fans are running at 7 volts - should be around 6db. Can't hear them until you stick your ear in the blades. They are attached with some clear 3M mounting tape. Runs just warm to the touch.
You can use symetrical power supply. But ACA was intended to be used with laptop PSU.
Output electrolytic capacitor is within feedback loop, has lower distortion than amplifier itself and serves as DC protection for your speakers.
If you want better amplifier look for another circuits, there are plenty of them - Aleph J, F6, F5, F4, M2, upcoming BAF 2015 amp etc.
ACA with Fostex fe108es
I am currently using the ACA monos with resistor mod from the diyAudio store with Fostex fe108eSigmas in inverted BIB cabs and they sound really nice and detailed. However, they are missing some of the powerful bass and fullness that my F2 amp gives.
Should I use a correction/baffle step circuit? If so, would that go in series or in parallel like with the F2? Any suggestions for values, etc?
Thanks!
I am currently using the ACA monos with resistor mod from the diyAudio store with Fostex fe108eSigmas in inverted BIB cabs and they sound really nice and detailed. However, they are missing some of the powerful bass and fullness that my F2 amp gives.
Should I use a correction/baffle step circuit? If so, would that go in series or in parallel like with the F2? Any suggestions for values, etc?
Thanks!
I have drawn the PCB some time ago. However I'm not sure if it is allowed to upload the gerber files (copyright?)
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