Re: ETI 477 schematic & pics
That might be fun. I still have the distortion analyser and sinewave generator that I used to characterise my amp. It'd be good to take some numbers from a live ETI5000.
feyef said:
That might be fun. I still have the distortion analyser and sinewave generator that I used to characterise my amp. It'd be good to take some numbers from a live ETI5000.
ETI 477
Suzy
The amp has been in a garage for a while with the cover off, so I am told there is a little corrosion here and there.
You will notice in the underneath photo that there are 2 zener diodes in series as I mentioned in a previous posting.
BTW, I was much less tidy 25 years ago.
Feyef will take it from here on.
SandyK
Suzy
The amp has been in a garage for a while with the cover off, so I am told there is a little corrosion here and there.
You will notice in the underneath photo that there are 2 zener diodes in series as I mentioned in a previous posting.
BTW, I was much less tidy 25 years ago.
Feyef will take it from here on.
SandyK
suzyj said:
Barf!
You're not brewing your own biodiesel are you?
I wouldn't want to be eating that much fish and chips.
ETI 477
Kevin
I have resent the AEM6005 schematic.
If anybody else is interested in a good quality copy of the AEM6005 schematic (only) ,send me an email . It is a 2.2MB file, so as to keep the details clear.
SandyK
Kevin
I have resent the AEM6005 schematic.
If anybody else is interested in a good quality copy of the AEM6005 schematic (only) ,send me an email . It is a 2.2MB file, so as to keep the details clear.
SandyK
G.Kleinschmidt said:
<grin> The usual technique is to get others to eat the fish and chips.
Alas, we're unable to make our own biodiesel, for the same reason that my framebuilding activities have been curtailed, in that the car occupies most of the garage. So we just buy the stuff, which is nice and clean, except that it's a bit of a hike to get it.
suzyj said:
OK, that's a relief! 🙂
I figured that if you were to compound the giving up on the pushbikes with such a diet, the results could be disastrous.
Cheers,
Glen
ETI477
Kevin
I recently received advice that the missing part of the AEM6005 project was undelivered. I have resent this email
SandyK
Kevin
I recently received advice that the missing part of the AEM6005 project was undelivered. I have resent this email
SandyK
sandyK could you send me the schematic please.
I was given one of these amps years ago and told the mosfets were blown up. I have never turned it on so is there some way of testing the mosfets in circuit?
I was given one of these amps years ago and told the mosfets were blown up. I have never turned it on so is there some way of testing the mosfets in circuit?
ETI 5000 amp for evaluation
suziej,
Please let me know if you are still interested in listening to/measuring sandyK's ETI 5000 amp. From memory, sandK's modifications made it sound quite a bit better than the standard version.
suziej,
Please let me know if you are still interested in listening to/measuring sandyK's ETI 5000 amp. From memory, sandK's modifications made it sound quite a bit better than the standard version.
Firstly, feyef, many thanks for the amp. It's a pity you weren't about when I dropped by. I'll have to find another excuse to come over though, as those speakers of yours look pretty amazing. I'll bet they sound wonderful.
I've surprised myself though. I didn't think I'd be able to tell the difference between my AEM6000 clone and the ETI5000. I figured that they'd both be reasonably similar, but so far they're actually audibly different.
After doing a quick DC check with a multimeter, and applying a wet finger to the HF shunt resistors to ensure there's no enormous oscillations, I hooked it up to my little study monitors (no Infinitys yet, until I've played through some slightly more easily replaced drivers for a bit), and played some music.
My selection: Old Dire Straits stuff, some nice noisy Led Zepp, Redgum, Crowded House, and Mike Oldfield.
For starters, the transformers in the ETI5000 give a lovely reassuring hum when it's powered up. Make you really appreciate all that wattage 🙂 My AEM6000 amps only hum for a second or three, until the field stabilises.
Also, I note the noise floor on the ETI5000 is somewhat higher than that of the AEM6000. The AEM6000 is really quiet - in between tracks it's as though there's no power on. The ETI5000 has some audible hiss, at least at good healthy power levels (yes, my husband is cowering in the corner - I think it was Smoke on the Water that was the final straw).
But even aside from this, it does have an audibly different character to the AEM amp. It's more raw, less clean. The AEM amp is just totally transparent, but this amp makes its presence known. I'd hazard a guess that it may even be breaking into oscillations a tad.
I must confess it's not actually a displeasing sound though. The sound is evocative of the smoky pubs that I was often to be found in as a teen 🙂 Or maybe that's just the music I'm playing through it?
Anyway, I'll sneak it into work through the week and bung the distortion analyser on it and see if I can't extract some numbers.
I've surprised myself though. I didn't think I'd be able to tell the difference between my AEM6000 clone and the ETI5000. I figured that they'd both be reasonably similar, but so far they're actually audibly different.
After doing a quick DC check with a multimeter, and applying a wet finger to the HF shunt resistors to ensure there's no enormous oscillations, I hooked it up to my little study monitors (no Infinitys yet, until I've played through some slightly more easily replaced drivers for a bit), and played some music.
My selection: Old Dire Straits stuff, some nice noisy Led Zepp, Redgum, Crowded House, and Mike Oldfield.
For starters, the transformers in the ETI5000 give a lovely reassuring hum when it's powered up. Make you really appreciate all that wattage 🙂 My AEM6000 amps only hum for a second or three, until the field stabilises.
Also, I note the noise floor on the ETI5000 is somewhat higher than that of the AEM6000. The AEM6000 is really quiet - in between tracks it's as though there's no power on. The ETI5000 has some audible hiss, at least at good healthy power levels (yes, my husband is cowering in the corner - I think it was Smoke on the Water that was the final straw).
But even aside from this, it does have an audibly different character to the AEM amp. It's more raw, less clean. The AEM amp is just totally transparent, but this amp makes its presence known. I'd hazard a guess that it may even be breaking into oscillations a tad.
I must confess it's not actually a displeasing sound though. The sound is evocative of the smoky pubs that I was often to be found in as a teen 🙂 Or maybe that's just the music I'm playing through it?
Anyway, I'll sneak it into work through the week and bung the distortion analyser on it and see if I can't extract some numbers.
suzy
I'm surprised to see that it is still working after all these years.
The 6,000 was much better !
SandyK
I'm surprised to see that it is still working after all these years.
The 6,000 was much better !
SandyK
suzyj said:
I've also heard both of these amps and still have an original AEM6000 is full working condition. Your appraisal of the sound quality difference is almost exactly the way I would have worded it. The 5000 seemed to exhibit a slight grainy quality in the treble and it highlights how smooth and silky the treble is in the 6000.
FTR I no longer use my 6000 because I've replaced it with my own derivation of the SC100W ULD class AB amplifier. I still use the 6000 as a reference amp because I'm so familiar with the sound but my new amp is better than the 6000 by about the same magnitude that the 6000 was better than the 5000 and in the same areas plus a few others.
ETI477
Suzyj
I can vouch for the claims of VHF man.
Current technology,and circuit techniques, has left the AEM6000,
and I am referring to this highly bleprinted version of the AEM6000 here, more suited for biamping at the low end.
VHF Man and myself both built "tweaked" AEM6000 amplifiers, which were much better sounding than most amplifiers of that time.
Valve Audio fanatics would probably love them ,though.
BTW, we are talking about the 240W RMS versions here.
SandyK
Suzyj
I can vouch for the claims of VHF man.
Current technology,and circuit techniques, has left the AEM6000,
and I am referring to this highly bleprinted version of the AEM6000 here, more suited for biamping at the low end.
VHF Man and myself both built "tweaked" AEM6000 amplifiers, which were much better sounding than most amplifiers of that time.
Valve Audio fanatics would probably love them ,though.
BTW, we are talking about the 240W RMS versions here.
SandyK
eti 477
the references to the eti 477 caught my interest.
while I lived in Queensland 1980-1982 I picked up PCBs
and built them up when I returned to the U.S.later in 1982.
IMHO you could do better, to me they were a little on the harsh side they measured well on my sound technology 1700b.
mine is still running in a relatives H.T setup.
so they are stable.
the references to the eti 477 caught my interest.
while I lived in Queensland 1980-1982 I picked up PCBs
and built them up when I returned to the U.S.later in 1982.
IMHO you could do better, to me they were a little on the harsh side they measured well on my sound technology 1700b.
mine is still running in a relatives H.T setup.
so they are stable.
There's good news and bad news...
I fired the ETI5000 up this morning before work on an 8 Ohm load, using a Tektronix SG505 oscillator to drive the input, and monitoring the output with an AA501A distortion analyser.
Quick first readings (I'll do more extensive tests at lunch time) indicate that the left channel does 0.0062% THD (50W, 1KHz). Not too shabby for a pretty old design. Sandy, did you have access to distortion mesauring gear when you built it?
The right channel, however, is a basket case. 0.35% THD (50W, 1KHz). The distortion doesn't drop as I vary the input level, either. It's so bad that it's actually visible on my cro (a 1GHz high zoot factor Lecroy).
No wonder it sounded interesting 🙂
Neither channel is oscillating though. I wonder what's causing the distortion? I presume capacitors have dried out. It is, after all, some thirty years old.
I fired the ETI5000 up this morning before work on an 8 Ohm load, using a Tektronix SG505 oscillator to drive the input, and monitoring the output with an AA501A distortion analyser.
Quick first readings (I'll do more extensive tests at lunch time) indicate that the left channel does 0.0062% THD (50W, 1KHz). Not too shabby for a pretty old design. Sandy, did you have access to distortion mesauring gear when you built it?
The right channel, however, is a basket case. 0.35% THD (50W, 1KHz). The distortion doesn't drop as I vary the input level, either. It's so bad that it's actually visible on my cro (a 1GHz high zoot factor Lecroy).
No wonder it sounded interesting 🙂
Neither channel is oscillating though. I wonder what's causing the distortion? I presume capacitors have dried out. It is, after all, some thirty years old.
right channel distortion
Hi suzij,
Any chance of poking around to determine which stage of the right channel is causing the distortion? I would like to bring it back to spec if I can.
Many Thanks
Hi suzij,
Any chance of poking around to determine which stage of the right channel is causing the distortion? I would like to bring it back to spec if I can.
Many Thanks
ETI477 article
Suzy
No , I didn't have access to such equipment. I am sure that the other channel would have been pretty similar to the other in performance originally, as the amp was far better than the Jaycar Gore Hill amplifier during a demo. Actually, I am quite chuffed that it is even working at all after all this time. Funny you should mention heat problems, as you will have noticed the extra scraps of aluminium added to try and overcome such problems.It's a pity we didn't have some of those nice screw on heatsinks back then.
SandyK
Suzy
No , I didn't have access to such equipment. I am sure that the other channel would have been pretty similar to the other in performance originally, as the amp was far better than the Jaycar Gore Hill amplifier during a demo. Actually, I am quite chuffed that it is even working at all after all this time. Funny you should mention heat problems, as you will have noticed the extra scraps of aluminium added to try and overcome such problems.It's a pity we didn't have some of those nice screw on heatsinks back then.
SandyK