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/i...origkw=accurian&kw=accurian&parentPage=search
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/i...origkw=accurian&kw=accurian&parentPage=search
A better opamp...
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!
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!
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
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
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
Regards,
David
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
Thanks Ben
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.
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
Ben
I would like to have Acurian amplifier schematic
If you have it boys, please, upload to uncle Charlie!
panzertoo@yahoo.com
regards,
Carlos
If you have it boys, please, upload to uncle Charlie!
panzertoo@yahoo.com
regards,
Carlos
phono jacks
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
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
It's easy...
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....
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....
Thank you for the prompt response.
"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."
I don't see a flat cable, but there is a 4 conductor[red,brown,black,yellow] cable plugged in at the edge of the sister board, going to the back of the LRMS switch. I can't find any labelling of the conductors or the sockets.
Which of the small circuit board should I remove? The sister board or the LRMS switch and its board?
[I've unplugged it at the LRMS-switch end and was planning to attach my RCA jacks at that end of the cable, but then I thought removing the LRMS switch assembly might not materially improve heat build up and perhaps you meant that the sister board should be removed and the RCA jacks attached at that end of the cable, leaving the LRMS switch intact.]
Any suggestion as to which color is right, right ground, left and left ground?
Thanks again for your help.
Regards,
Mike
I'm going to try to attach a photo. Hope it makes it.
http://public.fotki.com/mjd1258/accurian-40-162-amp/p1050440.html
"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."
I don't see a flat cable, but there is a 4 conductor[red,brown,black,yellow] cable plugged in at the edge of the sister board, going to the back of the LRMS switch. I can't find any labelling of the conductors or the sockets.
Which of the small circuit board should I remove? The sister board or the LRMS switch and its board?
[I've unplugged it at the LRMS-switch end and was planning to attach my RCA jacks at that end of the cable, but then I thought removing the LRMS switch assembly might not materially improve heat build up and perhaps you meant that the sister board should be removed and the RCA jacks attached at that end of the cable, leaving the LRMS switch intact.]
Any suggestion as to which color is right, right ground, left and left ground?
Thanks again for your help.
Regards,
Mike
I'm going to try to attach a photo. Hope it makes it.
http://public.fotki.com/mjd1258/accurian-40-162-amp/p1050440.html
Read the circuit board near the socket.
On the copper clad side of the board the switch is mounted to it says the what the pins of the socket are. The letters are small, but they are there.
On the copper clad side of the board the switch is mounted to it says the what the pins of the socket are. The letters are small, but they are there.
Went in to buy one of the Accurian amplifiers to power some SPICA TC-50s as computer speakers and the salesman had a pair of speakers also for 10 bucks. Said they were opened, but not used. I didn't really care for $10 so I didn't bother to check them at the store.
Got them home and the screws holding in the amp were part way out. Looking further the connector to the speaker and transformer were disconnected. Looking closer at the amp, the emitter resistors on one output are slightly cooked, what looks like the bootstrap cap and resistor load are both cooked. These would be R123, 124, 121, and C104. The top of the cap is bulging, and cracked open somewhat.
Anyone have a schematic?
Pete B.
Got them home and the screws holding in the amp were part way out. Looking further the connector to the speaker and transformer were disconnected. Looking closer at the amp, the emitter resistors on one output are slightly cooked, what looks like the bootstrap cap and resistor load are both cooked. These would be R123, 124, 121, and C104. The top of the cap is bulging, and cracked open somewhat.
Anyone have a schematic?
Pete B.
You still did ok!
Even is the amp is blown, the speakers themselves are well worth the 10 dollars you paid for them. Simply put a film cap across the nonpolar electrolytic and you might find these sound almost as good as the Spicas. I was surprised at how good they sound! I run a pair with a Sonic Impact "T" amp and they really sound good.
Even is the amp is blown, the speakers themselves are well worth the 10 dollars you paid for them. Simply put a film cap across the nonpolar electrolytic and you might find these sound almost as good as the Spicas. I was surprised at how good they sound! I run a pair with a Sonic Impact "T" amp and they really sound good.
Thanks, I actually got an amp for the SPICAs and the speakers and yes speakers alone for $10 are fine. I just want to fix the amp if I can, I've not even powered it up yet but I want to understand this failure mode, if possible, before I proceed.
Pete B.
Pete B.
Ok, only the 330 ohm resistor was totally cooked so I replaced it and the bulging cap. Applied power and the new 330 ohm got hot in a matter of seconds, powered down.
The 330 ohm seems to be the driver emitter load, so it seems that something is biasing the driver and output stages strongly on. The bad cap is actually the feedback shunt with a 1 K resistor in series.
The front end is comp differential, 100 ohm emitter degeneration, 8.2 K emitter load to a regulated supply. I think this is the same regulated supply for the OP amps.
I believe that the only way that that cap could be so badly stressed, it measured open, was for one of the diff transistors on the feedback side to have a base to collector short applying the full supply voltage to the 1K in series with the cap, probably in reverse.
I'm going to isolate the outputs by removing the 22 ohm base stoppers, .22 ohm emitter resistors and test them. Should probably just repace all the semis in that channel; none are expensive.
Drivers are: 2SA1023/2SC1027
Front end devices are: 2SA1266/2SC3198
VAS: 2SC1815
VBE-MULT: ??
The 330 ohm seems to be the driver emitter load, so it seems that something is biasing the driver and output stages strongly on. The bad cap is actually the feedback shunt with a 1 K resistor in series.
The front end is comp differential, 100 ohm emitter degeneration, 8.2 K emitter load to a regulated supply. I think this is the same regulated supply for the OP amps.
I believe that the only way that that cap could be so badly stressed, it measured open, was for one of the diff transistors on the feedback side to have a base to collector short applying the full supply voltage to the 1K in series with the cap, probably in reverse.
I'm going to isolate the outputs by removing the 22 ohm base stoppers, .22 ohm emitter resistors and test them. Should probably just repace all the semis in that channel; none are expensive.
Drivers are: 2SA1023/2SC1027
Front end devices are: 2SA1266/2SC3198
VAS: 2SC1815
VBE-MULT: ??
I don't have a schematic here so I'm tracing out some nets and making some educated guesses. Comp VAS looks to be: 2SA1266/2SC3198 not the other type as I stated above. Stoppers are 2.2 ohm, not 22.
Looks like drivers are actually: KTA1023/KTC1027
Anyone have a schematic? Pain in the neck tracing it out.
Outputs are blown, going to guess that the drivers are also, and probably more.
Pete B.
Looks like drivers are actually: KTA1023/KTC1027
Anyone have a schematic? Pain in the neck tracing it out.
Outputs are blown, going to guess that the drivers are also, and probably more.
Pete B.
my dad cut the red/black wires!
I think I can add a 3.5mm line-in port to replace the switch (top/left), according to directions here, but my Dad removed or cut the red/black wires that run up inside the enclosure. He was using this as a passive speaker, which was a shame.
Any idea what or where the red/black wires should connect to? if the wires went into a plug that was attached to one of the boards, he may have just cut the plug off the end, and if so I don't have it currently. Small chance he may have saved it, but doubtful.
Any help would be appreciated.
I think I can add a 3.5mm line-in port to replace the switch (top/left), according to directions here, but my Dad removed or cut the red/black wires that run up inside the enclosure. He was using this as a passive speaker, which was a shame.
Any idea what or where the red/black wires should connect to? if the wires went into a plug that was attached to one of the boards, he may have just cut the plug off the end, and if so I don't have it currently. Small chance he may have saved it, but doubtful.
Any help would be appreciated.
Attachments
I just pulled out the amp to mine, and the red/black pair go to a 2-wire connector on the main board near the back that is labeled SPK on the top and CN7 on the bottom. You can see the CN7 in your photo.
My speaker had been in constant use for many months, but has now stopped working. I'm guessing that the amp is working and it's just the receiver part that has failed, so I might want to do a RCA-in conversion. This thread is old, but hopefully it's enough to get me there. (I found this thread in a search...)
My speaker had been in constant use for many months, but has now stopped working. I'm guessing that the amp is working and it's just the receiver part that has failed, so I might want to do a RCA-in conversion. This thread is old, but hopefully it's enough to get me there. (I found this thread in a search...)