Old *** Sherwood Amp, Wiring Questions

[Suicide Bobb 5,000+ posts]

I have this ancient Sherwood SCP-1002 amp that i bought with many other amps that were untested/blown. My guess is that it was untested, because it does not tell you what wire colors correspond to what. There are two big wires, red and black, and one small wire that run seperate, which I would believe to be the power, ground, and remote. Then, there are 8 wires ran elsewhere in the amp. 4 black wires (all solid black), one blue, one red, one green, and one gray. Considering this is a 4 channel amp, these are most certainly the speaker wires. What I don't understand is which one is which. Usually, the wire runs to a spot on the circuit board which says "LR" or "RF" or something related to its location, but this one just has two letters from the color of the wire. Thus, the 4 black wires all are marked "B-L", the blue is "B-U", gray is G-A, green is G-R, and red is...B-R? Just to further confuse me, I guess. I can't find any info about this amp online, so does anyone here have any idea what color is what for the speaker wires? I have a feeling there would be an easy way to test out which is which, but I don't know personally.

Thanks,

-Dylan

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[Suicide Bobb 5,000+ posts]

Holy Shit! Under the assumption that the little black wires were common negatives, I grabbed a colored wire and a black wire, taped the rest off, and hooked it up to my 12v battery charger (to test car amps in my house). The little fucker works! i bought over 40 amps, from rockfords, to ppi's, to coustics, you name it, and the two that stood out as the shittiest looking were the Sherwood and a Kenwood Excelon, the Sherwood being the shittiest. The circuit board was a mess of gunk on the backside, and there were spider webs and what not everywhere. I am absolutely flabbergasted that the thing works. When I heard my sub buzzing after I turned it on, I dropped a load in my pants. It may be a Sherwood, but still...thats amazing

 

[Rodek 10+ year member]

I owned alot of Sherwood gear in the 80's. It was built tough. I am unable to recall what color went to which speaker however, you're correct. The colored wires are positive and the black are negative speaker outputs. I believe the amp was rated at 100 x 4 or 200 x 2 and was fused at 25 or 30 amp x 2. That's been a while so I may be slightly off. Regardless, you have a nice old school amp. Have fun!

 

[Suicide Bobb 5,000+ posts]

Yeah it is fused at 30Ax2 so I think 4x100w rms is probably right.

For anyone else who wants to know what colors correspond to what, here goes.

Big Red - Power

Big Black - Ground

Small Yellow - Remote

Small Green - Channel 1 positive

Small Red - Channel 2 positive

Small Blue - Channel 3 positive

Small Gray - Channel 4 positive

Small blacks - Channel 1,2,3,4 negatives

Now what I don't understand is what the "BTL1 & BTL2" are. I barely notice any difference when I turn them on. As for the Flat/Sub EQ switch, it doesn't make a difference besides the Sub EQ being louder. It still doesn't filter out the high frequencies, so I have to run my Audiocontrol crossover inbetween. However, without the filter, it didn't actually sound too bad above the low frequencies through the sub, although I only tested that for a few seconds.

 

[Rodek 10+ year member]

The BTL (Bridged Tied-Load) switches were used to bridge the amp. Not sure what the bridged wire connections were though. I don't believe they followed the standard practice of left channel positive/right channel negative for the bridged connection. Seems you used the positive speaker output on two channels to make the bridged connection (Channel 1 positive would run to your speaker's positive connection and amp channel 2's positive connection would go to your speaker's negative connection). This connection is similar to my 1980's Pyramid PB401A. It's up to you if you want to experiment. If I didn't already say it, Nice amp!

 

[Suicide Bobb 5,000+ posts]

Oh, ok. I think you are supposed to bridge channel 1 and 3, 2 and 4 because btl 1 points to channel 1 and btl 2 points to channel 2. I will try the left positive right negative, though. Will I risk blowing the amp?

thanks, btw.

 

[Rodek 10+ year member]

I usually err on the side of caution. I would probably try to get the correct bridged wire code first. But then again, if you don't have much invested, and trust the protection circuitry...it may be worth a shot!