Comments on: Speaker to Preamp Adapter for Jeremy

By: Keith Neufeld

Keith Neufeld — Mon, 21 Sep 2009 18:22:57 +0000

Roberto, the A502 is rated for 200W per channel.

By: Roberto Steve Lou

Roberto Steve Lou — Sun, 20 Sep 2009 15:21:59 +0000

Appreciated sir, I need to know how many watts pmpo or rms the sae a502 shoots.
Many blown speakers… I am in panama
How I know which are the appropriate speakers.
I have to MTX bass.

By: John Lindley

John Lindley — Sat, 28 Feb 2009 04:19:07 +0000

Slightly off topic but I did find the following little mixer very useful and I think it may well do what you are looking for.

http://www.studiomaster.com/products/C3&C3X.htm

I’ve used it a number of times for corporate events where I don’t really need anything more than mixing a mic with a couple of cd players.

By: Dave

Dave — Mon, 16 Feb 2009 23:08:45 +0000

I’m told that some early solid state amplifiers could also have trouble with mismatched output impedances. Thus, if I were to build one, I’d probably start with a suitable high power, low resistance resistor to load the amplifier and go from there.

Of course, the early way of doing this was with an L-pad:

http://en.wikipedia.org/wiki/L_pad

And, if you needed to maintain both the input and output impedance, you’d use a T pad (This is especially true to minimize the high pass or low pass characteristics due to inductive or capacitive loading.). Building an adjustable T pad is, of course, not trivial.

Dave

By: faustian.spirit

faustian.spirit — Thu, 12 Feb 2009 12:01:54 +0000

Depending on the capacitance of the preamp input and the connecting cable, lowpass effects could become considerable with such high resistor values used.

By: yellowduck

yellowduck — Sat, 07 Feb 2009 14:03:35 +0000

Hi, I keep an eye on your site, and by coincidence, an article on another blog http://synth-diy.blogspot.com/2009/02/it-wasnt-micas.html led me to a link that also discusses what you have achieved here http://www.musicfromouterspace.com/analogsynth/oddsandends.html#POTDIVIDER.

Keep up the good work. Cheers.

By: fatlimey

fatlimey — Fri, 06 Feb 2009 23:47:52 +0000

Excellent write up, especially showing the “obvious” circuit that I would have started with and explaining why that would be a dumb move. I hate tutorials that pull perfectly formed circuits out of thin air and proceed to explain about 15% of why they work.

Solving real problems with bits’n'pieces. More please!