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Audio Innovations Valve amps

thanks Guy - though the value on the caps there is 'only' 220 (2-hundred-20) uF/63V (they're Nichicons to date), the only higher value cap in the whole amp is a 10.000uF/63V one in the PSU, and everything is in the original state...
 
I do have the schematic (& set up instructions) for the Alto circuit if you want them. I still have one & it's an amp I'm very fond of.
 
many apologies, Guy, i AM really stupid, and many thanks for enlighting me: the caps are truly 2200uF ones. it's just been happening w/ me nowadays i dunno why that i see/read something and believe it being true but on second sight/reading it proves to be different... is it my starting to be silly, or am i 'just' ageing? brrrr, feeling worried...
anyway, i will send a mail to you asking for the schematics as i still have your address - and again many thanks :)
finally, take my highest and most honest appreciation for creating the Alto. i reckon few know it here how extremely great this lil' amp is shaming a lot of its today (!) peers even 3-4 times the price. it has been a recent revelation for me as i had had one put aside for years as spare for a time when i might happen to be w/o a 'decent' amp. and as the time has come with my 'serious' amp being recently sold it was dug out and fired - and my jaw dropped in spite the fact that the Alto was meant to only substitute a quite well-established valve amp until i find the big-name successor... what happened is that now my lil' old Alto became THE AMP in my not-at-all-basic system w/ each component costing many times its original price. hats off, man, really, what comes out from this tiny tot is MUSIC in the manner of the best of valves in capitals :)
 
We perhaps spent more time listening to & 'voicing' that amp than was spent on anything else. The competition at that price level was very fierce. Its biggest problem was that the Graham Allen designed case was too radical for the price it sold for. If it had been 2 or 3 times the price people might have taken it more seriously. Actually I still think its timeless & elegant. The matching CDP with John Westlake designed DAC was no slouch either.
 
I bought some 2nd Audios in May this year. They were horribly neglected and 20 years old. I sent them to David Wright for a service, based on recommendations seen here, and from being very impressed after speaking to him on the phone.
He replaced most of the capacitors, added earth lifts, and replaced the rectifiers with soft-clip types.
Unfortunately, one of the power valves got smashed on it's journey back to me after the work.
I bought a full set of Sovtek 6B4Gs, T-Cutted the case, and hey presto! They look like new. The sound was coarse initially, but started settling down after a couple of weeks. They now sound great.
It's been a long long time, but I can finally settle down and listen to some records!
David Wright has been a perfect gent from the outset, and has continued responding to my queries, and assisted with my problems (e.g. a dud valve, and an exploding capacitor).
I strongly recommend him if you want sympathetic treatment for your valve gear. His work is very neat and he knows his onions when it comes to component selection. Most important of all, he really loves and appreciates these amps.
 
David is. top man, you should hear his battery phono stage, and preamp absolutely superb as good as anything available.
Keith.
 
There is an AI Harmonie amplifier on offer. From what I can see from the photos, that's model 500. However, I wasn't able to find much info on the internet, at least not in English. Does anyone know how this model differs from a regular 500?

The amplifier has a problem with the input selector which, according to the seller, needs to be replaced. Is that an operation I could easily conduct myself and how much would the replacement cost? If not, what would be the estimated cost if I have it replaced by someone knowledgeable?
 
Harmonie was just a name added by the then distributors for Germany AudioPlan. IIRC the amplifier was the same as a standard S500.

The Dutch distributor used to mod each one he sold, mainly with some uprated electrolytic & coupling caps. I'm not sure the changes made were that significant.
 
Hello Gents,
You know how this hobby of ours never really seems to end? Well now that I finally have my 2nd Audios well fettled, and working with a Promitheus TVC, I find myself looking squinty eyed at the Promitheus.
The bass is rather loose and bloated, and the volume won't go low enough. I do love the clarity and the total silence though - I've never heard that before, and going back to my 6072A powered pre-amp seems out of the question - the noise is ridiculous.
My question to you all is, has anyone got experience of matching a pre-amp to the 2nd Audios? They are VERY sensitive. Maybe I could stick a series resistor on their inputs and go back to a valve pre? I don't know.
I am tempted to try a second-hand music first TVC, but if there's a good alternative out there that doesn't muck up the bass, I'd be all ears.
Any suggestions?
Craig
 
Hi i used to have 2nd audio's some years back .

i used a Concordant Excelesior valve pre with them with the gain set to low.

The original matching Innovations pre was the series 1000 ! this had a passive line stage so perhaps you might want to consider a high quality passive pre .

The loose and bloated bass you noted can be rectified (excuse the pun) by an external twin psu by Border patrol but very expensive , but oh boy do they sound much better with them ! .
 
Hmm,
David Wright said the BP PSUs would take the 2nd Audios into a World class product at a real world price. At £2,600 a pair though, I'll leave that particular upgrade for some future date when I am up to my teats in spare cash.
Interesting about the passive line stage though. I will start researching passives (resistive ones) - the only current one I've heard of (but not actually heard) is the Creek OBH22, which seems too cheap. I can't believe I've typed that - but for an unknown product there are so few clues to go on unless you can get recommendations/reviews.
There's also the intriguing Lightspeed thingybob which seems to be a DIY project, unless anyone knows differently. I have no idea how these things compare.
 
if i were you i'd rather wait and search the net until i find an AI pre for them being the safest bet - imho, of course. btw, art audio, croft and woodside pre's are great, too, with AI power amps, and turn up regularly on the web... moreover, ol' Glenn of Croft will fine-tune any decent pre for your AI kit i am pretty sure
 
I used to own a Classic 25 integrated. It was once measured 2 x 24 of extremely pure undistorted watts.
It drove a pair of medium-sized Magneplanars, and although the SPL was modest, it had a very warm, natural, engaging sound, slightly rounded off at the top.
My brother-in-law owned a 200/series pre-power for a while, similar sonic traits. My Classic 25 was one of the most lovable amps I've had, I still regret having sold it.
 
Out of interest, what speakers are you using?

Here's a commercial LDR pre.
http://diyparadise.com/shop/index.php?main_page=index&cPath=18

Here's another (with buffer)
http://www.myth.rs/myth_audio/mythpreamp.html

However, having tried LDR's & TVC's, I'd prefer an autoformer volume control from the likes of Intact Audio or Tribute.

You can buy ready made or assemble yourself.
http://www.intactaudio.com/atten.html

http://www.tribute-audio.nl/

These may well be the best sounding option with amplifiers having extremely high input sensitivity.

One other possibility might be this.
http://www.cattylink.com/page199.html
 
I am currently using Klipsch Heresies - horn hybrids of 94dB efficiency. They are slightly coarse, though and I am keeping my eyes open for a s/h pair of Audio Note E's. I have plumped for the E's for no rational reason - other that it's the same guy that brought us the 2nd Audios, and they will go close into the corner of my room.

There are a lot of options there - I really like the knackered look of the Intact Audio ready made units. Thanks for the suggestions.

What is it about Autoformers that diferentiates their performance from a normal TVC? I know it's all a single inductor with multiple taps, rather than separate coils on a common core - but what difference in performance does that bring?
 
I tried a couple of the Music First TVC's a couple of years ago (funnily enough with the 3rd Audio prototypes which also have highish input sensitivity). It was therefore necessary to use the TVC set so that it was attenuating alot & I didn't like it at all. I noticed that it did sound better the more it was turned up ie the less it was attenuating but that was not much use when the amplifiers had such high i/p sensitivity. Puzzled, I took the TVC upstairs & had a look at what it did with a squarewave which is usually quite revealing with wound components. Sure enough, when not attenuating, the squarewaves were perfectly fine but as you attenuated the signal by each step an increased amount of ringing appeared and by the time it was attenuating by as much as the position I was listening in the ringing was quite excessive. This isn't so surprising really. As the transformers attenuate more they are transforming more and their shortcomings become more obvious.

I was advised afterwards that the more recent Music First TVC's had addressed this problem but I haven't had the opportunity to test any.

The Autoformer volume controls, ie Intact & Tribute did not exhibit this ringing at all & I gather (although haven't tried one here), that the Promitheus rings even more than the MFA one.
 
That is fascinating. Thank you Puresound (again). I will pursue enquiries into the AVC arena.
Craig.
 
hello,
can somebody tell me which amplifier have better sound:

series 200
series 300 mk2
series 400 mk2
?
 
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