Has anyone built/listened to the playmaster Pro series 3 amp (Electronics Australia 1994).
I'm guessing that it can't be all bad if they are still selling 10 years on, but thought I'd see what people think.
Link to blurb http://www1.jaycar.com.au/productVi...&pageNumber=&priceMin=&priceMax=&SUBCATID=557
there is a Link to actual instructions including ciruit diagram on the above page, note big file approx 4.5MB.
Regards,
Tony.
I'm guessing that it can't be all bad if they are still selling 10 years on, but thought I'd see what people think.
Link to blurb http://www1.jaycar.com.au/productVi...&pageNumber=&priceMin=&priceMax=&SUBCATID=557
there is a Link to actual instructions including ciruit diagram on the above page, note big file approx 4.5MB.
Regards,
Tony.
Yes, I built one about 9 years ago.
It was/is the worst sounding amplifier ever designed/built in my opinion. Basically just a souped up Hitachi configuration out of their data sheet for MOSFETS. It totally killed my enjoyment of music. It sounds like a bad PA amp - grainy and harsh.
The funny thing is it was meant to improve on the old eti5000 amp of 1981, and yet the "Pro Three" is a far inferior design both objectively and subjectively.
The fact that Jaycar have been selling it for years doesn't prove anything - Tricky Dicky are still selling the ETI480 module (probably the second worst sounding amp ever designed)!
I would recommend looking up the Leach amp - you will find a link to it by searching these pages. It is a really musical and nice amp and as a bonus is just about blow-up proof. And it is designed by someone who knows what they are doing rather than a bunch of clowns at EA ;-).
It was/is the worst sounding amplifier ever designed/built in my opinion. Basically just a souped up Hitachi configuration out of their data sheet for MOSFETS. It totally killed my enjoyment of music. It sounds like a bad PA amp - grainy and harsh.
The funny thing is it was meant to improve on the old eti5000 amp of 1981, and yet the "Pro Three" is a far inferior design both objectively and subjectively.
The fact that Jaycar have been selling it for years doesn't prove anything - Tricky Dicky are still selling the ETI480 module (probably the second worst sounding amp ever designed)!
I would recommend looking up the Leach amp - you will find a link to it by searching these pages. It is a really musical and nice amp and as a bonus is just about blow-up proof. And it is designed by someone who knows what they are doing rather than a bunch of clowns at EA ;-).
I haven't built a playmaster Pro series 3 amp but have built 3 or 4 other amps. I would recommend an AKSA, might end up costing a bit more but well worth it IMHO.
http://www.aksaonline.com/index.html
http://www.aksaonline.com/index.html
ETI-480 Is Not All That Bad.........
With a few mods the ETI-480 makes an acceptably good entry level amplifier.
Faster output transistors, correct the power and earth arrangements and change a few passive components and these are reasonably good, easily available and cheap.
Eric.
With a few mods the ETI-480 makes an acceptably good entry level amplifier.
Faster output transistors, correct the power and earth arrangements and change a few passive components and these are reasonably good, easily available and cheap.
Eric.
Hi Eric,
I guess that's the difference between someone with an understanding of how the circuit works (and what can be tweaked) and someone like me who has only a basic understanding, but good enough soldering skills to build something someone else has designed!
I can make it but it will have whatever limitations were in the original design. You on the other hand can look at it and say hmmmm, I think it would be better if I changed this, and end up with something much better...... Maybe one day I'll be at that stage, but for the moment I'm concentrating more on learning about designing speakers.
I'm Looking at another amp, as I'm thinking of using my existing one for a sub amp and building a new one for the main speakers 🙂
Regards,
Tony.
I guess that's the difference between someone with an understanding of how the circuit works (and what can be tweaked) and someone like me who has only a basic understanding, but good enough soldering skills to build something someone else has designed!
I can make it but it will have whatever limitations were in the original design. You on the other hand can look at it and say hmmmm, I think it would be better if I changed this, and end up with something much better...... Maybe one day I'll be at that stage, but for the moment I'm concentrating more on learning about designing speakers.
I'm Looking at another amp, as I'm thinking of using my existing one for a sub amp and building a new one for the main speakers 🙂
Regards,
Tony.
Cheers.
To improve your ETI-480 do not use the existing power and output points (pins/pads) for power and speaker output.
Use fuses external to the module and bring B+ and B- to the board where the emitter resistors are connected.
Take the output from the track connecting the output transistor colletors (the existing setup causes causes imd because the NFB line is carrying speaker currents).
The speaker return line should go straight to the centre of the power supply and nowhere near the pcb.
Use a larger (10x) value low esr cap for the NFB shunt capacitor, and bypass this with a smaller value.
Use better/faster transistors for the outputs - I used Jap flatpacks - MJ15003/004 would be bullet proofing.
That's off the top of my head right now - 15 years since I did this - if you want I can take a closer look tonight.
These simple mods will improve the performance markedly.
Eric.
To improve your ETI-480 do not use the existing power and output points (pins/pads) for power and speaker output.
Use fuses external to the module and bring B+ and B- to the board where the emitter resistors are connected.
Take the output from the track connecting the output transistor colletors (the existing setup causes causes imd because the NFB line is carrying speaker currents).
The speaker return line should go straight to the centre of the power supply and nowhere near the pcb.
Use a larger (10x) value low esr cap for the NFB shunt capacitor, and bypass this with a smaller value.
Use better/faster transistors for the outputs - I used Jap flatpacks - MJ15003/004 would be bullet proofing.
That's off the top of my head right now - 15 years since I did this - if you want I can take a closer look tonight.
These simple mods will improve the performance markedly.
Eric.
Hi Eric,
My existing amp is actually a somewhat modified Playmaster Series 200 (mods all in the preamp section). Yeah I know It's probably even worse than the pro series III........ I've had some suggestions for improvement of it (power amp section) in another thread, which I'm yet to implement.
I'm looking to go for something fairly high end to replace it, not sure that a modified ETI-480 would be as much of an improvement over the 200 as what I'm after 🙂 (of course I could be completely wrong there!).....
Regards,
Tony.
My existing amp is actually a somewhat modified Playmaster Series 200 (mods all in the preamp section). Yeah I know It's probably even worse than the pro series III........ I've had some suggestions for improvement of it (power amp section) in another thread, which I'm yet to implement.
I'm looking to go for something fairly high end to replace it, not sure that a modified ETI-480 would be as much of an improvement over the 200 as what I'm after 🙂 (of course I could be completely wrong there!).....
Regards,
Tony.
The ETI 480 has been effectively superseded by the SC 480. It's on special this month at Dick Smith's for just under AU$40 per channel. I haven't heard one so I can't comment on the sonics but I woun't expect miracles as both the ETI480 and SC480 cheap output transistors. The enhancements mentioned will obviously improve the situation. I am building one of these at the moment and I suppose you can sum by saying "you get what you pay for."
I can't offer much on the Leach Amp other than the design looks very good and his web site is a great source for learning how these amps work.
I've just brought my second AKSA so I may be a little biased towards them. There are considered by many to be high end at a budget price, but I must admit I have not compared them myself to high end equipment. You might want to look here for more information and maybe find someone in your area to get an audition.
http://www.audiocircle.com/circles/viewforum.php?f=19
I can't offer much on the Leach Amp other than the design looks very good and his web site is a great source for learning how these amps work.
I've just brought my second AKSA so I may be a little biased towards them. There are considered by many to be high end at a budget price, but I must admit I have not compared them myself to high end equipment. You might want to look here for more information and maybe find someone in your area to get an audition.
http://www.audiocircle.com/circles/viewforum.php?f=19
owdeo said:
It could be a serious rival to the early Crown and Phase Linear squalid states as the worst sounding amplifiers of all time.
The Tilbrook amps were pretty good.
mrfeedback said:
Sorry, that's wrong Eric. It should read "To improve your ETI-480 use the existing power and output points (pins/pads) for power and speaker output." and needs to add "replace everything else" (including the original power and output points).
Pretty good if you could stop it breaking into oscillation. 🙄Brett said:
Back in 1980 I was able to compare two ETI480's I had with a friend's DC300A, and for a fact it sounded a bit better than the 480's. Had a stronger bottom end and the 480's by comparison seemed to have a very slight filmy haze over the sound. Not much though. What I do remember in particular though, is that when the 480's were driven from the matching IC150 preamp (which could slew 10v/uS at the output) the sound deteriorated into a very tiring, unsettling sort of thing that made you want to get up and go and do something else. With a slower preamp it sounded a lot better.
Circlotron said:
The only pair I ever heard were built by an RF engineer I worked with, so I bet those didn't oscillate. I recall it was quite good sounding driving my Linn Sara's.
That sounds like the Crown and PL poweramps, on everything
Hmmm All very interesting..... I can remember when I first got into electronics (would have been 82 I guess) the ETI 5000 was my holy grail, and I also wanted to make the matching preamp. Lucky for me I was still at school and couldn't afford it 🙂
My first amp was made on a piece of matrix board, was 10W/channel and used BD139 and BD140 for the output trannies (I think the original design called for BD130/131 but I couldn't get those). I'm not sure how many times I blew it up (didn't realise I needed to use mica washers on the heat sinks dohhhh...) So it may well rate as being worse than the Pro Series III 🙂....
I lent it to my cousin years ago, I'll have to see whether he still has it stashed away somewhere, might make an amusing picture!!!
Ahhh the good old days 🙂
grege I went to DSE's web site this arvo and thought the SC480 was $19.20/channel, are you including the PS? I must admit that $20/channel is pretty damn cheap for 100W! (woops just went back and looked and $20 is for the pcb only)........
Regards,
Tony.
My first amp was made on a piece of matrix board, was 10W/channel and used BD139 and BD140 for the output trannies (I think the original design called for BD130/131 but I couldn't get those). I'm not sure how many times I blew it up (didn't realise I needed to use mica washers on the heat sinks dohhhh...) So it may well rate as being worse than the Pro Series III 🙂....
I lent it to my cousin years ago, I'll have to see whether he still has it stashed away somewhere, might make an amusing picture!!!
Ahhh the good old days 🙂
grege I went to DSE's web site this arvo and thought the SC480 was $19.20/channel, are you including the PS? I must admit that $20/channel is pretty damn cheap for 100W! (woops just went back and looked and $20 is for the pcb only)........
Regards,
Tony.
There is one In Every Crowd..........
Eric.
Brett, the sarcasm gestapo will be around to slap you when you least expect them - you have been forewarned.Brett said:
Eric.
Don't Ever Let A SMPS Guy Build Audio Amplifiers.......
If it was oscillating, then you were not doing it right.
With much better output transistors, electrically more correct connections to the pcb and some component changes these do not have to be bad - quite good in their day really.
I reckon any amp with 2N3055/2955 sounds hazy and rough, and such transistors are best used in a regulator or something not audio.
For the dollars they make an aceptable racket - mine were in big demand for a heap of parties in my formative years.
Eric.
Circlotron said:
If it was oscillating, then you were not doing it right.
With much better output transistors, electrically more correct connections to the pcb and some component changes these do not have to be bad - quite good in their day really.
I reckon any amp with 2N3055/2955 sounds hazy and rough, and such transistors are best used in a regulator or something not audio.
For the dollars they make an aceptable racket - mine were in big demand for a heap of parties in my formative years.
Eric.
Re: There is one In Every Crowd..........
I think they know I'm not afraid to slap back.
mrfeedback said:
I think they know I'm not afraid to slap back.
Excellent comments Brett! And keep up the sarcasm.
Yeah I think Tilbrook has a good set of ears - very musical amps.
I would just like to add that anyone who wants an amp to enjoy music through should avoid Silicon Chip magazine designs at all cost. ;-)
Yeah I think Tilbrook has a good set of ears - very musical amps.
I would just like to add that anyone who wants an amp to enjoy music through should avoid Silicon Chip magazine designs at all cost. ;-)
It was the ETI series 5000 thing that oscillated, not the 480.mrfeedback said:
There was this issue of the inductance of the wire wound mosfet source resistors. The original used IRH brand, lots of other people (including me) used Noble. The "fix" was to put a cap between the two lower sources. It helped somewhat but you could never crank it right up without it spitting the dummy. It did sound WAY better than the 480's though. They were a disappointment. Was driving a pair of JBL L19's BTW.
This was back in April '81; didn't know much about SS amp tweaking in those days. Even now it's not my speciality.
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