Dean MARKLEY K-150

[lo-watt]

Anyone have this schematic?

[TomCarlos]

Take a look here - https://elektrotanya.com/dean_markle.../download.html

Looks like you can also buy the schematic from MusicParts.com.

[lo-watt]

I was looking for a free one. Don’t think my customer wants to pay for one.

[Enzo]

So download the free one from Elektrotanya.

[lo-watt]

I do not trust Elektro...just my preference. Seems my antivirus blocked them quite a while back anyways if I recall.

[lo-watt]

Was hoping someone had a copy downloaded personally.

[Jazz P Bass]

"So download the free one from Elektrotanya. "
OK

dean_markley_k-150_sch.pdf

[lo-watt]

Thank you!

[vintagekiki]

I do not trust Elektro...just my preference. Seems my antivirus blocked them quite a while back anyways if I recall.

Update and configure your antivirus.
I've been using Elektrotanya for many years, I've never had a problem with viruses.

[DrGonz78]

They drop cookies on your computer and many times that causes antivirus programs to shoot out a false positive. The AV program may think it's a tracking cookie or something. Probably the cookie is harmless but don't eat too many before bed time.

[J M Fahey]

Warning: I very much like Dean Markley amps, simple and inexpensive but always sound good, but they made a mistake here: they use far cheaper switching Mosfets (IRFxxx) instead of original Audio ones (2SK/2SJxxx) but they did not update the Bias system.

Old style ones could use a simple resistor, as shown, but switching MosFets NEED a thermal tracking bias, with a sensing transistor attached to the heat sink, period.

So you have 2 options:

* use as is, but bias it **cold** , allowing for some crossover distortion.
If your customer always plays it LOUD, he won´t notice it.
But at bedroom levels it may be annoying.
I suggest you play the amp loud, into speakers or a resistive load if unbearable, for at least 10/15 minutes so heatsinks are hot, and only then adjust bias, and then to minimum needed only so you see creossover almost dissappear on scope screen.
It will be buzzy at bedroom levels but usable and safe loud.
If you adjust it to be sweet sounding in a bedroom, it may self burn when played loud.

* the proper solution, mod bias to thermal tracking one, such as the one used by Ampeg (and all others):