Recent content by cubeasic

I use an old Trygon Dl40-1: https://www.surplusselect.com/products/trygon-dl40-1-electronic-dual-lab-supply-0-40-vdc-1-amp-max-sold-as-is It has two independent 40V supplies. Good for poweramp idle testing.

Cool video. It is a family owned company with additional 6 employes. They come from the south west of Germany, a highly industrialized area of Germany where they have the reputation to be the most diligent. Porsche, Mercedes and Zeiss have their headquarters there. In the same spirit he is a...

I can take a photo and mark the relevant positions. This might take a few days though. You can consult the available service manual, there are part values in the appendix. I think only two different tant-types were used, 100 uf and 22 uf.

So the electrolytics should be fine. Are the voltages before and after the regulator ok? Before around 60V, after around 40V. There are also tant caps at several places that eventually could be replaced. Maybe one of them shorted...

Have the amps been recapped at some point? "Too hot to touch" in idle is definitel a little bit too hot. It might be a good idea to open the hot amp, and see if anything is obviously wrong. Follow the available service manual (via Google) for this. While you are at it you can make a recap at...

Wow great. I haven't looked at this thread for a couple of years.... really impressive.

I use moode audio as OS with several pi-versions. Moode works well as a streamer (probably the primary purpose) and also has a good and easy to use mode to use it as a bluetooth renderer. The PiTop you mention does not work with the usual DAC-hats you find for the rpis. You probably need a USB...

Ok, that is reassuring. I will keep the 2k7 and 200pF. I figured that stability could be an issue, even though the transformer would provide low pass filtering by itself.

Thanks for the feedback. Much appreciated. I guess I‘ll try it soon, and check for DC offset in the process. The problem in my case goes a little bit further. I use a balanced output buffalo DAC and would like to use the unbalancing transformer at the hacker nap input (10k:10k Sowter 3575)...

Hello, This is maybe a dumb question, but as I understood it once, with Hackernaps and NCC amps, the 2,7k and 24k resistor an the input are the counterpart of the 27k feedback resistor, presenting nearly equal resistance to the long-tailed pair inputs (from output and GND, respectively). In...

I sometimes fancy about the picoscope 4262: https://www.picotech.com/oscilloscope/4262/picoscope-4262-overview It promises an all in one solution with low distortion signal generator and low noise 16 bit oscilloscope, optimized for analog signals. Does anyone have experience with with one?

Regulated or unregulated? Hypex produces a range of very well unregulated split supplies. Only a limited choice of output voltages though.

You have to cut two PCB tracks that go between input- and output-stage. They run at the outer sides of the PCB from back to front. Then you can feed the frontend separately. The regulated rails run at around 40-41 V. You can built a LM317/37 supply with provisions for the higher voltages...

The paralleling of secondaries is common practice on smaller transformers like Block Print transformers. As long as the secondaries have the same VA rating and impedance the basic requirements are met. The phases of the secondaries should be identified or measured beforehand because they should...

I am aware of the LM317 limitations, and used the LM317 also for Hackernap-FE-duties with the protection diodes you mentioned. From the LM317 cocooning I also got the idea of protecting the Fetlington-FET with a zener diode.