Check polarity of mosfets, soldering of source resistors, and shorts under the keratherm.
Polarity is correct (9240 for P; 240 for N); source resistors solder good; no shorts on Mosfets if I did it right (checked Drain Pin to Ground).
Attachments
PS wiring is bit hard to track as it is routed underneath the bottom plate. I labeled the wires in the photo. My M2 and F6 builds went without a hitch. This was suppose to be a quick and dirty build but it is making me work for it.
Attachments
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It looks like you’ve got your power supply turned inside out after you split the PCB. (The LEDs should be on the inside) It’s one of those things that might not matter if you are really clever and were planning on doing that , but all the labeling will be backwards...
Double-triple check your voltages and connections and such.
Double-triple check your voltages and connections and such.
It looks like you’ve got your power supply turned inside out after you split the PCB. (The LEDs should be on the inside) It’s one of those things that might not matter if you are really clever and were planning on doing that , but all the labeling will be backwards...
Double-triple check your voltages and connections and such.
They are but I didn't think that would matter as long as the V-, V+ and GND were connected properly. Will check everything again today. Thanks for taking the time to look at the photos!
Okay, found it. V- and GND are reversed on the PS board. I looked at that at least 5 times and redid the wiring twice while assembling (was done correct first time then brain must have focused on orientation instead of actual labeling on the board second time). Nice example of why not to rush even if you think you know what you're doing.
Fantastic!! Good news!
Thank you for all your help. I think I would have stared at the wiring for a week before noticing the mistake if you hadn't mentioned the PS boards.
That’s the whole point of posting the photos... you need different eyes to see the mistakes.
What preamp are you driving the amp with?
I have a PassLabs XP-10. But the main reason for wanting to try the F4 is to drive it with a 2 watt DHT amp I have.
Thanks! I plan on using with a Bottlehead amp also. Been listening to it with the XP10 and it is quite different than I was expecting (could certainly use more gain than the XP10 provides). Sound field is very upfront/forward with lots of detail (which I expected) but soundstage is more a wall of sound than 3-dimensional. There is little to any center image and voices fill the whole space between the speakers, or just sound like they are coming from both speakers. This is quite different from the F6 and M2 I built. Those do have dual mono power supplies, but I have other amps that do not (Audio Research and Conrad Johnson) that have much more 3-dimensional soundstage. My former PassLabs Int-60 also provided a much more 3-dimensional soundstage. Will give it a whirl with the Bottlehead but right now I prefer the F6 and M2 much more.
Not imaging? That's not right. It's an imaging machine, probably the best of the series... Check to make sure everything in wired and connected in proper phase.
Nailed it again 6L6...one speaker was hooked up out of phase.
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