70's and 80's AMPS

Madmike2

Member
2005-04-24 11:55 pm
Toronto
I did a brief look back at past posts looking for this answer. I didnt find it. Are the old monster AMPS of the 70's and 80's all class A ? and AB ?
I am finding tons of these things for sale in Buy and Sell and E-bay but i am a bit nervous about buying them. I know i wont get a tube project going like i thought i would as i am running out of my yearly alotted toys money.

I already missed out on the guy in Canada with the monster amp near Collingwood. SOmeone point me towards a good amp for my new subs :)

Oh and mabey a smaller one for the top end as well. might as well stay in one decade :D
 

Madmike2

Member
2005-04-24 11:55 pm
Toronto
I didnt know Bob was doing anything back that far .... :D
He looks way to young :)

80's sure but 70's ?

Sub power isnt the only thing as i was more then a little curious to see what the overwhelming opinion was. I have seen a few posts where people have said that 70's and 80's were far beefier amps.
 
Sub power isnt the only thing as i was more then a little curious to see what the overwhelming opinion was. I have seen a few posts where people have said that 70's and 80's were far beefier amps.
Like everything else, it depends on the $$.

The more inexpensive amps from that era were certainly better built than the more inexpensive ones now, if that's any way to level the playing field.
 

SY

diyAudio Moderator Emeritus
2002-10-24 10:19 pm
Chicagoland
www.SYclotron.com
FWIW, I've got a 1985-vintage Adcom 555 driving my subs (JBL 2245Hs in sealed, downfiring 300 liter enclosures). Despite numerous hacks and lots of abuse, it keeps on ticking. Fine amp.

Phase Linear were the contemporaries of Kawasaki H1/H3 and were of a kind: wild, unpredictable, and a tendency to self-destruct.

Crown DC300 were solid, but watch out for aftermarket output transistors.

Threshold amps were excellent, but not cheap.

Kenwood had some nice monoblocks with a unique feedback sensing system. I still see them around from time to time.

A real score would be a pair of Onkyo M510 monoblocks.

And, of course, Macintosh was as solid as it gets. Quite cool looks.
 

Madmike2

Member
2005-04-24 11:55 pm
Toronto
EchoWars said:
Like everything else, it depends on the $$.

The more inexpensive amps from that era were certainly better built than the more inexpensive ones now, if that's any way to level the playing field.


It levels just fine, it just goes to prove, to me anyway, that they did it right back then. They let the bean counters come and tell them to do it better 'cheaper' which is rarely better.
\
My plan is to find a nice pair of 2 channel amps or find 2 amps that look reasonably similar. I am not spending 499 on some current Pioneer POC when i can score 2 'old' amps that are probably better for that money and have more power and class AB or A. NOT class H T Z and L or whatever the flavour is now.

and yes i think that anything with a B was Mr Carvers. I was being Facisious when i said he looks too young :) . No offense Bob, i had a Sunfire for awhile. :D
 

taj

diyAudio Member
2005-02-23 8:49 pm
Brystons

I've always liked Brystons too. I have a pair of 4B's from the early-mid 80's that still sound fantastic. One for my sub, one for my main left-right pair. I'm still looking for the perfect [DIY project] amp for my tweeters so I can run tri-amped.

..TAJ
 
For $180-250 you can get a Kenwood M2 power amp with the Sigma Drive (feedback sensing SY was talking about). For Subs, its VERY nice, I have a couple of them bridged running JBL 2226's.

Damping factor on those is 1000, 220wpc RMS into 8 ohms and 350wpc 4 ohms. (Do not run below 4 ohms).

Glass-G, runs VERY cool.... great value.
 
Since Phase Linear came up in the thread, I'll mention that www.phaselinearhistory.com and http://hometown.aol.com/PhaseTek/ are full of info on the topic.

However, there is a cool factoid they omit (I think) Pink Floyd used banks of PL700's (modified) on tour because the pro units of the day were not not up to the job. Appearently without bursting into flames as some claim.
 
You know what the sad part is ? I have been in and out of audio in some way or form for the better part of 20 years. I still never bothered to learn what some things did or or why what i did worked. I would go to a club and set it up. I would go to a wedding or party and set it up. I would go with (R.I.P) my mentor Craig Newell and build and or map out theatre layouts for wiring and speaker placement. I would build and or design subs and build-outs for hi end car audio and not care why it worked or how i was winning IASCA events.

Now i truly do wanna know the hows and there is too much info. I hear things. I know whats wrong and i know why but i dont know how i fix it. If it sounds wrong i know and most of the stuff i hear today sounds wrong. It all seemed to sound better in the 80's. Take Tannoy for example. The old stuff sounded great now its cold and 'off' i dont know why. I have asked questions here , cracked a few jokes and had some interesting e-mail chats with other curious folks like me. And even though i was steered towards something. I still woke up one day and my head said "buy old class A stuff, avoid new yamaha" or something along those lines.

I dont want to ask too many more questions because they inevitably lead to more. I know what class g is now and most of the others. Give me inefficient and hot anyday if it sounds better.

Is it just me getting older or is there something going on with the new gear ?
 
What about the Crown DC300A (got me into opamp drive and complex phase comp) or Phase Linear 700B - wasn't that Bob Carver?

Having repaired hundreds of both these amps I can state that both of these were class B output stages. Nasty x-over notch at higher frequencies and doubly nasty looking distortion content no matter how the bias was set. ESS had a 250 watt p ch power amp for a few years that sounded the best of those 1970's amps but it was very prone to self destruction.

BUT... these do make good chassis upon which to build a decent class AB power amp. Nothing fomr the 70's was really any good, so my favs from the 80's were in order......

The early Krells... KSA-50 and 100

Thresholds 800A, and later 400A

The SAE Jim Bongornio designed amps.

Beyond these there isn't anything solid state from that time period thats worth the time of day.

Mark