View Full Version : Audio Innovations Series 200 Power Amp
I wonder if anyone here can tell me the input impedance of this above-named amp?
Spectral Morn
13-12-2009, 11:39
I wonder if anyone here can tell me the input impedance of this above-named amp?
Send a PM to Guy (Pure Sound) he should be able to help as he once worked for Audio Innovations. Very nice guy and has a lot of audio related knowledge.
Also could you pop into the Welcome section of the forum ans say Hello, tell us a wee bit about yourself and the music and system you have...Thank you.
Regards D S D L
Send a PM to Guy (Pure Sound) he should be able to help as he once worked for Audio Innovations. Very nice guy and very as a lot of audio related knowledge.
have done so at PFM but no reply so far...
Also could you pop into the Welcome section of the forum ans say Hello, tell us a wee bit about yourself and the music and system you have...Thank you.
Regards D S D L
sure, will - if really required. am not truly an outgoing chap..., though the community is great here, as concluded :)
Didn't Guy *design* these amps too?????
Spectral Morn
13-12-2009, 22:28
Didn't Guy *design* these amps too?????
Not sure Dave....its to long ago...I can't remember.
Regards D S D L
pure sound
13-12-2009, 23:29
Early versions had 470K on the input. The 200 Mk2 had 220K.
I didn't design the original circuit but had a hand in the revised Mk2 version.
thanx man, a lot :)
i'm entirely enthralled by all the ai products - i reckon they're still 'the best' regardless of price :)
hope your puresound business would be that successful - both financially and time-stand-wise :) (dunno how to say exactly - meaning would stand the time like the ai gear)
pure sound
14-12-2009, 14:10
There were a few AI products which were less good in their original form and which needed to be revised to make them more reliable & better sounding. Some of the efforts to make pentode amps without feedback spring to mind.
But most do still stand the test of time. One of my favourites still, although not a valve amp, was the little Alto amplifier which not only looked good but sounded great (& very different to the SS norm). That doesn't seem to have been 'discovered' yet but it will be!
dunno, i had both the series 300 mk i (spaceship) and mk ii (4-legged, in both the /strangely/ so-named mk i and mk ii guise - strange since it was in itself an mk ii version), and the series 400 mk i and mk ii versions, and to my ears in each case the original model sounded more pure and tonally well-balanced. imho the later models did improve frequency extremes and dynamics, but in the meantime - again, imho - some MUSIC was lost...
to note, i read your 'ranking' of the ai range containing models that you favoured over the others though, and i believe technically the upgraded versions must have been more perfect. also, neither am i to question that these mk ii, iii, etc. models fitted better your (i.e. the ex-ai team's) musical preferences.
of the little wonder, the alto: yes, i share your view regarding its sonic merits :) however, i reckon the relatively low power and the un-availability of the major parts (e.g. power transistors) for a thorough service may well distract people from going for it...
Rare Bird
14-12-2009, 18:31
But most do still stand the test of time. One of my favourites still, although not a valve amp, was the little Alto amplifier which not only looked good but sounded great (& very different to the SS norm). That doesn't seem to have been 'discovered' yet but it will be!
:doh: One i dare not mention for the fear of getting killed , i've had the Alto & matching CD, they are great your right
pure sound
14-12-2009, 20:48
dunno, i had both the series 300 mk i (spaceship) and mk ii (4-legged, in both the /strangely/ so-named mk i and mk ii guise - strange since it was in itself an mk ii version), and the series 400 mk i and mk ii versions, and to my ears in each case the original model sounded more pure and tonally well-balanced. imho the later models did improve frequency extremes and dynamics, but in the meantime - again, imho - some MUSIC was lost...
to note, i read your 'ranking' of the ai range containing models that you favoured over the others though, and i believe technically the upgraded versions must have been more perfect. also, neither am i to question that these mk ii, iii, etc. models fitted better your (i.e. the ex-ai team's) musical preferences.
of the little wonder, the alto: yes, i share your view regarding its sonic merits :) however, i reckon the relatively low power and the un-availability of the major parts (e.g. power transistors) for a thorough service may well distract people from going for it...
The 300Mk1 (in its ugly box & then slightly prettier box) was better than the Mk2 version (4 legs) mainly because the original ones had the very fine Hinchley transformers in them. (Hinchley used to make transformers for Leak amongst others) Unfortunately they were taken over by Tamura & stopped making audio transformers. The same applied to the S500 although early 500's were like a rats nest & poorly put together whereas later ones were more production engineered. An early 500 with the original transformers, but rebuilt by the factory later, is a very nice sounding amp.
Early versions of the EL84 amps (200 & 400) were pure pentode designs without feedback. Very fast & clear but limited at the frequency extremes & lacking in load tolerance. The later 200 Mk2 was a more sensible UL design iirc. I don't think the 400 was ever really sorted out properly.
The 800 & 1000 powers also flirted with the no feedback approach in their Mk2 guises but reverted to more sensible UL designs in their Mk3 iterations.
The Alto amp has very common & easy to find output transistors, 2N3055 if I recall. It is quite easy to service with no difficult to obtain devices within.
Andre, The Alto CD player had a fairly elaborate DAC, designed by John Westlake who did all of the Pink Triangle digital stuff so that, in combination with the amp could punch well above its weight.
Spectral Morn
14-12-2009, 21:04
The Alto Amplifier and CD player are still available (I think) from all Richer Sounds stores in the UK. Richer bought out AI at the end of its life (killed the valve designs) exclusively for the Alto designs. I thought at the time that this was very sad, as AI played a very important part in my early to mid period audio experiences.
I want to thank Guy, Peter Q and Eric Anderson (thanked him in person already) for AI. No brand is perfect (AI got it wrong sometimes) but when they were right WOW.
I started on a Series 300, then Series 500 (which I still have) and recently got a set of series 1000 mk3s which I use every so often with an EAR pre, that matches well.
I have no idea if the modern Alto is just the case design with poor insides (compared to the original)or the same. I remember when it came out and I must say that at the time (and it did sound well) that I thought this was the end of AI and valves and that was what happened ultimately.
Anyway Guy...Thank you for your contribution to what AI was during PQs time and after.....:cool::) Those were fun days.
Regards D S D L
The 300Mk1 (in its ugly box & then slightly prettier box) was better than the Mk2 version (4 legs) mainly because the original ones had the very fine Hinchley transformers in them. (Hinchley used to make transformers for Leak amongst others) Unfortunately they were taken over by Tamura & stopped making audio transformers. ...
thanx for the explanation, highly appreciated :)
Early versions of the EL84 amps (200 & 400) were pure pentode designs without feedback. Very fast & clear but limited at the frequency extremes & lacking in load tolerance. The later 200 Mk2 was a more sensible UL design iirc. I don't think the 400 was ever really sorted out properly. ...
i see - still, my safest bet with ai is the series 400 mk i :)
The Alto amp has very common & easy to find output transistors, 2N3055 if I recall. It is quite easy to service with no difficult to obtain devices within. ...
okay, you surely know it much better - and thanx for assuring me about it. once i might buy one again for just the sake of it... ;)
The Alto Amplifier and CD player are still available (I think) from all Richer Sounds stores in the UK. ... I have no idea if the modern Alto is just the case design with poor insides (compared to the original)or the same. ...
to my best knowledge, the RS-guise alto is (almost) a completely new design with a radically different circuit and, thus, sound from those of the ol' alto's... :(
Spectral Morn
14-12-2009, 22:31
to my best knowledge, the RS-guise alto is (almost) a completely new design with a radically different circuit and, thus, sound from those of the ol' alto's... :(
Thats what I thought, but I wasn't sure.
Regards D S D L
Rare Bird
15-12-2009, 00:54
Andre, The Alto CD player had a fairly elaborate DAC, designed by John Westlake who did all of the Pink Triangle digital stuff so that, in combination with the amp could punch well above its weight.
Why do i always get rid of the good stuff & keep the crap? Well it's easy i'm a dick ed :lol:
Pure Sound or anyone here in the know, which amp do you think would 'better' fit my Rega Ela 2000s (btw who knows where my topic has gone?) sonics-wise, the S200 MkII or the S400MkII?
Rare Bird
16-12-2009, 18:52
(btw who knows where my topic has gone?)
Well if it don't fit into the new Flat Earth ideology it will have gone ;)
hi, guys,
I seek advise now - I wonder whether you could help me? Namely, I am hesitating to replace my SS amp for the Audio Innovations Series 200 MkII Power with 12W (4xEL84s) on tap. Do you think it would drive the Rega Ela 2000s sufficiently? Earlier I had the Quad 22L2s and there was no problem with the S200's capabilities, though the Quads' impedance stayed over 6 Ohms, rather between 6-11 Ohms, and I am not sure of the Elas' load. Unfortunately I can't match them before the buy... Any views appreciated :)
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