Radio Shack Accurian speaker/amps

[dpuopolo]

Radio Shack is closing out their Accurian Home Plug audio speaker/amps for 19.95. These contain a pair of 2 way speakers (good build quality and very decent sound). One cabinet has a built in 25 watt/channel amplifier similar to the 15 dollar
Accurian power amp discussed elsewhere here.

These can easily be modified by removing and discarding the power amp receiver daughterboard and mounting a pair of phono jacks on the back for audio inputs. They make GREAT powered computer speakers!

You can improve the sound a bit by bypassing the input caps (there are another pair after the volume control) and by replacing the 4558 opamps with TLO72 or 82's (these seem to be the only
opamp upgrades that work well with these). The TLO82's are also sold by Radio Shack for 1.99 each.

Even if you don't use the amp, the speakers alone are worth at least 100.00 for the pair.

Here's the link:

http://www.radioshack.com/product/in...entPage=search

[dpuopolo]

The opamp power supplies in this unit are quite current limited, so many opamps will not work well in its circuit. This includes the 5532. Originally, I replaced the (marginal) 4558 opamps with TLO82's that I bought at Radio Shack. Made a noticeable difference, but this still wasn't what I'd consider hi fi.

Today my sample TI TLE2082 opamps arrived. These are upgrades to the TLO82, featuring much higher slew rates and a larger gain bandwidth product. They work GREAT in these speakers!

NOW this is truly hifi....and WELL worth 5X the paltry price!

[gtforme00]

dpuopolo

Thank you for the heads up! I picked up two pair of these speakers at a small town Radio Shack for 14.97 a pair! Have you played with the internal crossover at all? It looks to me like it is a simple series electrolytic capacitor affair on the tweeter and the woofer runs free. I'm going to add RCA inputs today and give them a listen. I'll order some of the TLE2082s and give them a shot as well.

Any more information on these?

Thanks,
David

[gtforme00]

I added the RCA jacks to these and connected them to my computer. They do sound very good for the price. One thing I noticed is that the TO-92 transistors (drivers?) which are against the heatsink have heatsink paste on them but have no clamping mechanism to the heatsink. When i pulled my amp out they were not in contact with the heatsink at all. This could cause the amp to go into thermal runaway if they are relying on thermal coupling of the driver and output transistors.

Regards,
David

[ben62670]

I just bought some of these speakers, and I am using them as my puter surrounds. I also have the amp only for my front Polk/Morel ported T/M's. It sounds surprisingly good. I would however like to replace the output transistors. Anyone do this mod? On my amp only I bypassed the tone controls, and kept the volume, and balance.
Thanks Ben

[Eva]

If the coupling capacitors of a potentiometer are removed and even small amounts of DC are allowed to flow through the wiper, in most cases it will become noisy quite fast.

[ben62670]

I think I got lucky with matched transistors in the signal path. I get no DC offset. My concern is the output is a little rough. I am not using any of the op amps in the pre board.

Ben

[destroyer X]

If you have it boys, please, upload to uncle Charlie!

panzertoo@yahoo.com

regards,

Carlos

[mjd1258]

I just bought a set of those speakers at radio shack, and of course the Audio Sender unit is not to be found.
Is there anyone who could give me elementary installation instructions for adding phono jack inputs?
I'm not at all versed in electronics. I assume the smaller board is the receiver and the larger board is the amplifier? I was hoping to recognize a connector between the two which I could separate and rewire to a set of new input jacks, but there seem to be a lot more there than I expected to see. Any assistance would be greatly appreciated.

I intend to use this as a single speaker, not wiring in the satellite speaker. Is there any truth to the idea that an amplifier can be damaged if it's not connected to a speaker? If so, does switching to mono take care of the problem?

Regards,
Mike

[dpuopolo]

It's the four conductor thin flat cable that has two small white plugs on it. One end runs to the daughterboard (which is the smaller of the two circuit boards), the other end plugs into a small circuit board on the back of the speaker that has a slide switch on it labelled L, R, M,S. You unplug it from the small circuit board which you then completely disconnect and remove (less heat builds up with it gone).

If you look on the sockets this cord plugs into, it's even labelled
L,R, LG, RG. These correspond to Left, Right, Left ground, Right ground.

It couldn't be any simpler....