That is way too low and I couldn't use that amplifier with my 5V headunit. So I'm just SOL because these are old school.
You could always add a voltage divider or attenuator to drop the voltage. That would require a few resistors at most.
When high-voltage line drivers (and consequently Head Units) began to get noticed, the Sedonas' inputs were typical of amplifiers. Few, if any, had high-Z inputs rated for more than 1V.
High voltage line drivers allowed competitors to turn their amp gain control all the way down in an effort to reduce noise, which remains the only good reason to have a line level signal that high.
I have a 5v headunit and my old a600.2's dont' have a problem with it. Their gains are almost maxed, too. Let me go check the booklet and see what the max input level is supposed to be...
Btw, just won a nob alphasonik FA 100! Very cool forced air cooled amp. Just wanted to get one to look inside, lol. The guy also sold an hcx 2150 and FA 200, both were under $50 shipped, like mine was 😀
Btw, just won a nob alphasonik FA 100! Very cool forced air cooled amp. Just wanted to get one to look inside, lol. The guy also sold an hcx 2150 and FA 200, both were under $50 shipped, like mine was 😀
ppia600 said:
just won a nob alphasonik FA 100! Very cool forced air cooled amp. Just wanted to get one to look inside, lol.
The insides of old Alphasoniks aren't glorious. American design, 80's Korean build. Typical mosfet supply with TIP35/36 outputs.
However they did sound good (as good as anything to average ears), and their price (per real watt) had few rivals that were worth having.
All my opinion, of course - but regular experience with RF, Orion, PPI, Zapco, Autotek, Linear Power, H/K, A/D/S, Alpine, Kenwood, Blaupunkt, MTX, Denon, and a slew of peripheral brands during that time period is what the opinion is based on.
I can't comment on the FA 100, but have been curious if it's just a PMA 2050 with a fan & shroud. The PMA 2050 had chronic problems with overheating one area of the PCB, followed by failure. The previous version (MA-2050) didn't have this problem, nor did any other of their amps during that era.
It could also be that the fan took the place of limiting for more 2-ohm power, as A/MA/PMA series amps were rated for the same power @ 2 or 4 ohms.
Speaking of the Alphasoniks I have been looking for the rare and tiny handmade (German) David 265 (just because its diffrent).
Let me know if you find one for sale.
Always though this was a cool amp.
http://ampguts.realmofexcursion.com/AMA_Stereo_50_MKII/
-JH
Let me know if you find one for sale.
Always though this was a cool amp.
http://ampguts.realmofexcursion.com/AMA_Stereo_50_MKII/
-JH
It may have the same exact audio circuit design, but the board layout is totally different. There is an aluminum tunnel going right down the middle so the transistors are going to be mounted on either side of it. Kind of like the denon dca 800 car amp and several of the home amps. Or even the kenwood kac 921. Surely more reliable than the non fan cooled models. I had a pma 2175 and that thing was ultra powerful, I managed to somehow fry it though. 🙁 I never had a chance to get it repaired, couldn't find the correct parts and was too busy with work back then.
I also spoke to the guy I got it from and he said he had the plexi one and would let me know if was going to sell it. He also agreed to let me know if he comes across any of the larger pyramid/ppis like the pbsb2075 I got. 🙂
I also spoke to the guy I got it from and he said he had the plexi one and would let me know if was going to sell it. He also agreed to let me know if he comes across any of the larger pyramid/ppis like the pbsb2075 I got. 🙂
tsmith1315 said:
The insides of old Alphasoniks aren't glorious. American design, 80's Korean build. Typical mosfet supply with TIP35/36 outputs.
However they did sound good (as good as anything to average ears), and their price (per real watt) had few rivals that were worth having.
All my opinion, of course - but regular experience with RF, Orion, PPI, Zapco, Autotek, Linear Power, H/K, A/D/S, Alpine, Kenwood, Blaupunkt, MTX, Denon, and a slew of peripheral brands during that time period is what the opinion is based on.
I can't comment on the FA 100, but have been curious if it's just a PMA 2050 with a fan & shroud. The PMA 2050 had chronic problems with overheating one area of the PCB, followed by failure. The previous version (MA-2050) didn't have this problem, nor did any other of their amps during that era.
It could also be that the fan took the place of limiting for more 2-ohm power, as A/MA/PMA series amps were rated for the same power @ 2 or 4 ohms.
ppia600 said:It may have the same exact audio circuit design, but the board layout is totally different.
I had a pma 2175 and that thing was ultra powerful, I managed to somehow fry it though. 🙁
That's nice to know. If they bothered to redo the board, I'm sure they would have revamped the problematic circuit as well. Looks like another item to add to the collection!
BTW, The 2175 would produce almost full power (350W) with only one channel driven into 4ohms -not bridged mind you, just leaving the other channel disconnected! Potent, and about the price of what, a Punch 75 and a couple of six packs? No contest.
I still have a variety of 2035's, A-265's, 2055's, A-255's, and maybe another or two that are forgotten, along with a pair of D6200 4" plates.
As much as I love the high end stuff, there was rarely a case when the typical customer *should* have forked out the cash for a more expensive amp than these.
Jonny H, that David 265 is ultra cool.
Can't imagine that it would be a powerhouse, but I'd love to check one out! The David name is a hark back to the days when Alphasonik was the American counterpart to the German Visonik company with their successful line of David speakers.
Jonny H, that David 265 is ultra cool.
Can't imagine that it would be a powerhouse, but I'd love to check one out! The David name is a hark back to the days when Alphasonik was the American counterpart to the German Visonik company with their successful line of David speakers
I had always assumed that because the amp was so tiny (I remember someone say it would almost fit in the palm of your hand) and that it put out a surprising amount of power for its size that it was a biblical "David and goliath" reference.
Learn something new everyday!
-JH
Love the Alphasonic's. Not really a high end amp, but they were some of the first ones most people could afford way back when. I had a bunch of them... Still have 3 of the bi-amp racks. 2 are still new in the original boxes. Looking for a tri-amp rack if anyone has one.

tsmith1315 said:
The insides of old Alphasoniks aren't glorious. American design, 80's Korean build. Typical mosfet supply with TIP35/36 outputs.
TIP35/36 were the "in" thing in the late 70's and 80's. Zapco 150 and 151 series 2/3-piece amps had them in their outputs on the amp section. (as did a lot of amps) Pic of the inside of the amp section of a 151. Not much to it, but they sure sound nice.

Speaking of 151's, what's the word on the Honda?
I know, wrong forum...this made me think of it though!
Ben
I know, wrong forum...this made me think of it though!
Ben
and of course I couldn't resist...
🙂
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An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
🙂
It has been on hold. Ran out of extra funds, but will hopefully be back on it within a week or two. Selling off more of the old-school collection to get some funds together. I will have the 34" sub mounted this weekend or next. Will keep the link on DIY updated as soon as I get back on it. Thanks for asking...benlebow said:Speaking of 151's, what's the word on the Honda?
I know, wrong forum...this made me think of it though!
Ben
Till then, here are some new pics of the 150's and 151's. I think 2 sets are not pictured. (need some more ESM's if anyone has any extras) . Plus here is a pic of the Linear Power amp's guts.





So this board was designed by someone in Berkeley? I wonder if the entire amp was assembled in the US?
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Jonny H:
That may well be where the Visonik David name originated, as their David speakers were bookshelf or smaller. Very similar to A/D/S, and used Braun drivers, too.
The "Little Davids" were 5-1/4" with 1" dome in a small box, which carried over into a line of Visonik car speakers with the "Little Davids" sold enclosed or in plate form as the 5200. Their car speakers rivaled the best at that time, and I actually preferred their 5200 and 5-1/4" separates to the gold-standard A/D/S 300i and 320i.
The car speakers started to phase over to the Alphasonik name around '84 with the D6200's, the separates, 6-1/2, and 8" woofers -all German made. The woofers had neat-looking cast aluminum heatsinks on the magnets.
tomtomjr:
Man could live on 151's alone.
I think *I'm* going to cry. At least sulk...
Aaaaarrrgh! Like an even dozen is not enough??? I just want one more to make a measly three complete sets!
I had always assumed that because the amp was so tiny (I remember someone say it would almost fit in the palm of your hand) and that it put out a surprising amount of power for its size that it was a biblical "David and goliath" reference.
That may well be where the Visonik David name originated, as their David speakers were bookshelf or smaller. Very similar to A/D/S, and used Braun drivers, too.
The "Little Davids" were 5-1/4" with 1" dome in a small box, which carried over into a line of Visonik car speakers with the "Little Davids" sold enclosed or in plate form as the 5200. Their car speakers rivaled the best at that time, and I actually preferred their 5200 and 5-1/4" separates to the gold-standard A/D/S 300i and 320i.
The car speakers started to phase over to the Alphasonik name around '84 with the D6200's, the separates, 6-1/2, and 8" woofers -all German made. The woofers had neat-looking cast aluminum heatsinks on the magnets.
tomtomjr:
Pic of the inside of the amp section of a 151. Not much to it, but they sure sound nice.
Man could live on 151's alone.
I think 2 sets are not pictured.
I think *I'm* going to cry. At least sulk...
(need some more ESM's if anyone has any extras)
Aaaaarrrgh! Like an even dozen is not enough??? I just want one more to make a measly three complete sets!
ppia600 said:So this board was designed by someone in Berkeley? I wonder if the entire amp was assembled in the US?
Very cool amp. There seem to be a couple of give aways to the build. AFAI remember, the 80's models also had the Berkeley reference. Seems like the Class "A" models claimed "technology under license by Threshold" in the manual. They were designed in the US and made in Korea, thus the ability to sell them at more affordable prices.
I guess they were ahead of their time in that respect.
The board design is the same as the older models -as in single sided with familiar looking traces, the same green solder mask, and no silk screen layer on bottom. But the top side in your amp looks much cooler in flat black then the raw phenolic color.
(It is definitely neater inside and looks easier to disassemble than the older models.)
As well, the interior hardware looks like the previous Korean bits, but the external stuff does not.
I'll take apart an older one in a couple of days to check my memory and compare, but I dread the individual mica insulators...
Definitely one for the collection.
Do you have power ratings or paperwork other than the test certificate?
tsmith1315 said:
tomtomjr:
Man could live on 151's alone.
I think *I'm* going to cry. At least sulk...
Aaaaarrrgh! Like an even dozen is not enough??? I just want one more to make a measly three complete sets!
Hey Tim,
You really ought to think of giving up your 151's. They are old, out of date, and just collecting dust. You could send them to me, and I will feed them fresh TIP 35/36's and give them a good home. They need to be with the rest of the herd. 😀
Nope, that was all I got. He said it was new without a box. I'm also hoping he'll give me first crack on the clear one. Then I'll put this one up for sale. I forgot to mention there were about four cracked solder joints that I touched up before powering it up. Didn't expect to find them but I guess over the years it could have been thrown around a bit, lol. And it works great 🙂
tsmith1315 said:
Very cool amp. There seem to be a couple of give aways to the build. AFAI remember, the 80's models also had the Berkeley reference. Seems like the Class "A" models claimed "technology under license by Threshold" in the manual. They were designed in the US and made in Korea, thus the ability to sell them at more affordable prices.
I guess they were ahead of their time in that respect.
The board design is the same as the older models -as in single sided with familiar looking traces, the same green solder mask, and no silk screen layer on bottom. But the top side in your amp looks much cooler in flat black then the raw phenolic color.
(It is definitely neater inside and looks easier to disassemble than the older models.)
As well, the interior hardware looks like the previous Korean bits, but the external stuff does not.
I'll take apart an older one in a couple of days to check my memory and compare, but I dread the individual mica insulators...
Definitely one for the collection.
Do you have power ratings or paperwork other than the test certificate?
tomtomjr:
A brief synopsis of the ensuing dementia generated by that post:
😕 WHAT? Not possible, they're genetically attached.
😱 HERESY! How can you force yourself to type that, even in jest?
You know, there's probably a mob already forming.
They're chanting," tomtom... tomtom...tomtom..."
You can't possibly sleep tonight.
OK, I finally see your plan.
The car audio evangelist calls to reunite all 151's in a "Back To Modesto" Movement. We all feel sorry for them, because they should be with their siblings and send them westward. But they get cut off at the pass, then get rounded up for eternity in Texas...
Think you can pull a fast one on a ol' southern boy, huh?
Maybe it's time to go out and check on them, I'm kinda concerned.
A brief synopsis of the ensuing dementia generated by that post:
You really ought to think of giving up your 151's.
😕 WHAT? Not possible, they're genetically attached.
They are old, out of date, and just collecting dust.
😱 HERESY! How can you force yourself to type that, even in jest?
You know, there's probably a mob already forming.
They're chanting," tomtom... tomtom...tomtom..."
You can't possibly sleep tonight.
They need to be with the rest of the herd.

The car audio evangelist calls to reunite all 151's in a "Back To Modesto" Movement. We all feel sorry for them, because they should be with their siblings and send them westward. But they get cut off at the pass, then get rounded up for eternity in Texas...
Think you can pull a fast one on a ol' southern boy, huh?
Maybe it's time to go out and check on them, I'm kinda concerned.
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