Dead BHK 300

One of my amps refuses to power up. Checked fuses. Seem ok. Gosh I don’t want to have to send the beast back. And was just getting ready to test the new dac2 which I haven’t heard while burning it in. Any ideas?

Fuses appear fine… the ‘white’ ones also look fine but I don’t know what a bad one would look like - assume you can tell if blown?


Just replace the fuse.

Invest in a digital voltmeter and test each fuse for continuity. -And forgive me if I underestimated you.

Hey @woodburger - Would you mind letting us know how you’ve determined that the fuses are OK?

Number one on my list of “best practices” is to keep a stock of spare fuses for every component. Just the garden variety so cost is negligible.


Especially since RS is not just down the street anymore.

Luckily I had some spare fuses from PS.

Checked continuity on all 6 in the amp. The clear glass ones test ok on VTM. The white ones, not. Replaced them and powered up. And it did.

So relieved.* Sure can’t tell from looking at them that the white ones were apparently blown.

*Update: blue logo light now lights but amp doesn’t pass audio.


Tested clear fuses again. All ok. But now I am getting no volume on left amp, distorted volume on right side.

So, to summarize, all fuses on left amp, ok -

AC power shows to BHK pre and dac 2 plus transport 2.

No audio left channel. Right side distorted.

Swapped cables to amps, no change.

Now I don’t know if issue is with pre, transport, new dac, or left amp.

I shudder at the thought of sending all of it back.

Any ideas?

Did the system go from working to suddenly not working?
If you haven’t, I would shut everything down, remake every connection and light it all up.
I had a similar experience and it was just the hdmi cable that slipped out just a bit.

Lots of trouble shooting. Seems the left amp is the problem: no audio, even with another CD player plugged into rca input; tried l and r output of that player… amp not passing audio.

Right amp seems fine as it plays back ok (input rca from surplus player.)

I had been burning in dac2 w no audio playing for 250 hours. Finally wanted to listen to New dac2.

Agree I will try unplugging and reconnecting everything. Good advice! I could pull the tubes and try replacements but the tube set has under 3000 hours on it.

3000 hours is a pretty big number for a power amp so if you have spare tubes change them out and if not swap the good ones in the working amp to the other one. Sure beats a large shipping charge during the Holiday shipping season.

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Unplugged and replugged all. The left amp will not pass audio. Tubes are lit.

I was thinking tubes as well.

The tubes are input tubes, not output tubes; should last longer.

But I agree, swapping or replacing tubes is worth a shot. I have confirmed issue is not my cables, not the dac2 (though I’ve still not heard but one channel playing.). Not pre either as I bypassed it entirely, driving amps w surplus player (20 years old or more.). And that resulted in no audio left channel too.

Sure seems no music for Xmas. Hate to package and return amp now.

Just because the filaments are lighting up doesn’t mean the tube is working properly, not saying the tubes are the problem. Try the tubes out of the working amp.

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Will do and report back.

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I’ve forgotten, how many fuses are there inside?

IEC and four rails.

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Tube swap: from working amp to non-working amp: tubes play on “good” amp, no audio with them installed in “bad” amp.

There are 6 fuses per amp, all accessible from outside amp, btw. If there are any INSIDE I don’t know. (and why?)

I wasn’t sure if there were any inside. I was just poking at another avenue.

So far you’ve:

  1. Tested fuses
  2. Swapped tubes
  3. Swapped cables from left amp to right amp

What’s left?