Huge AEA Analog 620 power amp ?
- Thread starter Chap
- Start date
Ken Leonard
New Member
I'm Ken Leonard, the designer of the AEA preamps and amps.
The AEA 620 has a four-quadrant bridging output design. This is basically two class AB amps, both driving the speaker "bridged" between them. The two AB amps are driven 180 degrees out of phase, so one amp is going positive while the other is going negative. This results in twice the voltage across the speaker that a single class AB stage would develop. Each channel should develop 300 watts at 8 ohms, 600 at 4 ohms and 1000 at 2 ohms. If one side of the bridging amp is out, it would cause the power to lower to about 100 watts.
I'm happy to answer any questions anyone might have about the AEA amps... I can be reached at ken @ kenleonard dot com
The AEA 620 has a four-quadrant bridging output design. This is basically two class AB amps, both driving the speaker "bridged" between them. The two AB amps are driven 180 degrees out of phase, so one amp is going positive while the other is going negative. This results in twice the voltage across the speaker that a single class AB stage would develop. Each channel should develop 300 watts at 8 ohms, 600 at 4 ohms and 1000 at 2 ohms. If one side of the bridging amp is out, it would cause the power to lower to about 100 watts.
I'm happy to answer any questions anyone might have about the AEA amps... I can be reached at ken @ kenleonard dot com
Chap
Electrochap
Thanks a lot Ken !
Finally an answer! Unfortunately I don't have this amp anymore. I would have dig deeper...
I also was using the pre-amp for a while and I liked it very much! I replaced it with a ML-1 so it can't be shy about this. Pre amp was a very good one as well as the amp!
Both pre amp are using those "little secret" opamp black module (the Mark Levinson were filled with black epoxy). I never tried to open those in the AEA as everything was working well (I had to replace 2 modules of the ML1...hard to find ans quite expensives). So maybe I should have kept the AEA... Was smartly built with a separate power switch for the switched equipment powered with it! great idea never done anywhere else I think.
So Thanks again Ken and I may will get to you with some other questions!
Have you design other equipment after AEA? I saw some stuff looking like them a few times but don't remember the name.
Finally an answer! Unfortunately I don't have this amp anymore. I would have dig deeper...
I also was using the pre-amp for a while and I liked it very much! I replaced it with a ML-1 so it can't be shy about this. Pre amp was a very good one as well as the amp!
Both pre amp are using those "little secret" opamp black module (the Mark Levinson were filled with black epoxy). I never tried to open those in the AEA as everything was working well (I had to replace 2 modules of the ML1...hard to find ans quite expensives). So maybe I should have kept the AEA... Was smartly built with a separate power switch for the switched equipment powered with it! great idea never done anywhere else I think.
So Thanks again Ken and I may will get to you with some other questions!
Have you design other equipment after AEA? I saw some stuff looking like them a few times but don't remember the name.
We hate to resurrect such an old thread, but just an FYI to anyone who owns an AEA 515 phono preamp, 520 preamp, or 620 power amp, WE ARE BACK IN BUSINESS!
My father, Ken Leonard, the original founder and designer of gear under Analog Engineering Associates, Inc. ("AEA"), and I have recently restarted the company to get back into the audio industry. While we are focusing now on tube gear, we will service any of our legacy products at no charge beyond the cost of parts. We may not be able to find exact factory replacement parts, but we can certainly repair any problems a unit may be having, and can bring any unit back to factory specs. So dig out any AEA gear you may have, and feel free to contact us about servicing them.
My father, Ken Leonard, the original founder and designer of gear under Analog Engineering Associates, Inc. ("AEA"), and I have recently restarted the company to get back into the audio industry. While we are focusing now on tube gear, we will service any of our legacy products at no charge beyond the cost of parts. We may not be able to find exact factory replacement parts, but we can certainly repair any problems a unit may be having, and can bring any unit back to factory specs. So dig out any AEA gear you may have, and feel free to contact us about servicing them.
Last edited:
Ken Leonard
New Member
Sorry, for the very long delay in responding.
I don't recall the Canadian distributor... I was mostly involved in the design side of the business.
Also, I didn't design any audio gear after AEA. My partner shut down AEA to concentrate on designing computer graphics systems used for "special effects" in the TV broadcast industry.
AEA was originally in the recording studio electronics business, until we started building high-end audio equipment on a challenge from Eric Clapton to build a solid state preamp that sounded better than his AR SP3. The strange story of how all that all happened in on our website: AEAaudio.com
Ken
I don't recall the Canadian distributor... I was mostly involved in the design side of the business.
Also, I didn't design any audio gear after AEA. My partner shut down AEA to concentrate on designing computer graphics systems used for "special effects" in the TV broadcast industry.
AEA was originally in the recording studio electronics business, until we started building high-end audio equipment on a challenge from Eric Clapton to build a solid state preamp that sounded better than his AR SP3. The strange story of how all that all happened in on our website: AEAaudio.com
Ken
markdi
Natural born thread killer
really
read the topology description of the analog 620 amp
a adcom gfa-1 has 2 50 watt bridged amps per channel
to put out 200w 8 ohms
350w 4 ohms
I own 3 of them
one has a low channel
one of the 50w amps in one of it's channels has a problem
sounds perfect just low output
glad I amused you
love to find a analog 620 someday
read the topology description of the analog 620 amp
a adcom gfa-1 has 2 50 watt bridged amps per channel
to put out 200w 8 ohms
350w 4 ohms
I own 3 of them
one has a low channel
one of the 50w amps in one of it's channels has a problem
sounds perfect just low output
glad I amused you
love to find a analog 620 someday
rcspkramp
Super Member
Welcome back to the business. Got a website that we can all peruse?We hate to resurrect such an old thread, but just an FYI to anyone who owns an AEA 515 phono preamp, 520 preamp, or 620 power amp, WE ARE BACK IN BUSINESS!
My father, Ken Leonard, the original founder and designer of gear under Analog Engineering Associates, Inc. ("AEA"), and I have recently restarted the company to get back into the audio industry. While we are focusing now on tube gear, we will service any of our legacy products at no charge beyond the cost of parts. We may not be able to find exact factory replacement parts, but we can certainly repair any problems a unit may be having, and can bring any unit back to factory specs. So dig out any AEA gear you may have, and feel free to contact us about servicing them.
See post #26.
sae-7125
Super Member
since the original tech docs and specs no longer exist upon the material sphere, would it be possible to recall idle wattage for the 620 amp (with or without load connected)? the quad bias seems to be interesting since there are 4 amp channels per channel for the double BTL (bridge tied load) circuit design. having an idea of "how high is too high" for the bias pots would be a good safety net. dim bulb ever present when tackling the quantum unknown.
dc offset seems to be relatively stable although i will be doing a mediocre attempt at a deep dive into the amp over on my diy>menagerie thread. the aea account on ak seems to have low activity history, ever so sad (last seen 24mar20).
Ken are you still on this forum? I see the last post was from 2013. I have a AEA 620 and absolutely love it, do you know how many were made?
Midwestmusic
New Member
Did you ever find out any more information about your 620 amp from AEA? I also have the 620 and I am looking for any more information that people have collected over the years.
sae-7125
Super Member
i am guessing that you found some worthwhile info in another thread, since my "alerts" counter went to the moon.
the 620 definitely has some ability to exercise just about any speaker efficiency even magnepan.
