Recent content by dlucy

There's a great question just asked: the HK 730 and HK A-402 power amp stages are very similar; the Harman Kardon 730 receiver's PHONO stage, when recapped, is awesome; is the PHONO stage in the HK A-402 integrated amp the same as the one in the 730? Let's take a look: The HK 730 PHONO stage...

you guys are pushing my OCD hard... I'm >this< close to buying a 930 just to figure it out....

Agreed. If you can't get the mV down into the 50mV range, then you may need to either: replace some components (hard to do) or increase the bias resistance by adding a resistor to the trimpot (thereby increasing the range of resistance it can apply)

So, several things: Disconnect your speakers. No reason to risk them, no reason to keep them connected. Use a 10 watt or higher 8 ohm resistor instead of a speaker. Connect each of these load resistors to the speaker terminals as if they were the speakers. As @jheu02 points out above, attach...

The Harman Kardon twin power series, e.g. 430 630 730 and 930, are direct-coupled instead of cap-coupled (like the prior everything). These twin-power-transformer receivers are more powerful, more modern, but also more neutral-sounding as there are no capacitors immediately before the speakers...

If you write it down, it's science. I like science.

Those black tubes on the foil side are not bridges; rather they are resistors, still part of the circuits, and covered in a black non-conductive tube. They are necessary for proper operation of the board. Here are my before & after photos.

If you will start a new thread in the Solid State forum, I'll respond there.

No matter what brand or model of gear, I never expect the PHONO section to produce the same level as the TUNER or any other inputs. How much signal you get is the result of the cartridge, any step up transformer you have between it and the amp, and the PHONO stage in the amp. You can expect it...

Interesting idea:

https://audiokarma.org/forums/index.php?threads/fm-stereo-demultiplexor-ic-chip-ba1310-lm1310-nte801-ecg801-all-the-same.785294/

If it is just the Left channel, then Q304 is suspect. Replace that and see what happens. Of course, if that ends up being the problem, you'll want to replace both Q304 and Q303. Assuming the device you have at Q303 and Q304 is actually what the schematic says, 2SA844E, then a good replacement...

@abruno17 keep in mind you are asking for a recomendation here. As per AK rules if you want AK'ers who have something to sell you to reply, you'll need to add a WTB (want to buy) thread in the Bartertown Equipment forum.

When you say "static", which of these do you mean? Constant hiss or snap-crackle-pop? This is likely a transistor "gone bad over time" Mostly crackle only when adjusting volume, balance or tone controls? Something else?

Use the highest HFE you have and that will be fine.