Audio Innovations Series 1000 Mk 3 and Series 500 Integrated Amplifier

[Spectral Morn]

HI Chris and Jonathan

As promised, some photos of one of a pair of AI s 1000 mk 3 50 watt class A valve amplifiers. I will post a photo or two of my Series 500 when I can release it from its place of storage. Photos now done.

Audio Innovations Series 1000 MK3 mono valve power Amplifier.









Audio Innovations Series 500 25 Watt Class A integrated Valve amplifier

This amplifier was my first true love. Used over 15 years in a number of systems and in two homes. This amplifier was designed by the legendary Eric Anderson. Eric wanted the amp to look one way and Peter Quartrup this way. I am glad Peter won but when I met Eric a few years ago at a Hi-Fi show and we talked about the design of the 500. He asked me "Does it still work ?" then with a smile he said "Do you use it with a fan ?" No I said. He told me about his concerns for overheating. This being the reason he wanted it to look another way. Like some silly Fan ...I thanked him for the amp, as it had given me years of pleasure. Thank you Eric Anderson, I am a FAN.

Amplifier with no valves in place.



Side view showing Tiffany Rcas fitted to chasis. These replaced the poor quality ones that were mounted to a very flexible board, which bent in when you attached good quality heavy cables. Sounds better too.



Front view. Tesla EL34 valves on back row. Mullard NOS yellow label EEC 83 in middle. To far left JAN Philips 6922 (ECC 88) and to far right Gold Dragon ECC83.



Rear of amplifier. Early series 500 amplifiers had three speaker output taps 4/8/16 Ohm. Later models only had two. The output transformers in earlier amps are said to be better as well.




Regards D S D L----Neil

[chris@panteg]

Hi Neil that looks in lovely condition ' a very nice amp ' just love the design , Gary Dews demonstrated this amp with one of his Border patrol PSU units i think back in 1997 it sounded amazing.

It looks a very late model with the textured paint finish .

[Mike]

Throw those Golden Dragon ECC83's in the bin though... They're nasty!

Pop a pair of Mullard or Telefunkens in there though, and!....

[Spectral Morn]

Hi Mike and Chris

The amp dates from about 1990. The previous versions, two I think had black paint finish. I thought the textured finish was better at the time. Peter Q was still in charge of AI when I bought the Amp. The Series 1000 date from Guys time in charge.
Latter versions aren't as good as this one and the previous ones.

Chris I like to keep my kit like new...so I take care of it. I have all the boxes for all my kit too...the roof space is bunged.

The Gold dragons are not what I use normally(in the past), I could not find the valves I used (I think they are in something else I use, maybe my EAR pre...not sure. It was what I could find to take the photos with. I used to use Gold Aeros which I got from Zia of Tube technology. I have a pile of Mullards that I will need to test. I have a 1950's TV repair mans valve tester. It wont give readings for matching, but it does say if the valves are good or not. I'll take a picture later and post it here.

Regards D S D L----Neil

[pure sound]

The Mk3's were the properly sorted version of that circuit and could sound very good indeed (especially the silver edition SE version)

regarding the Series 500, the earlier ones were pretty unreliable for various reasons mainly the internal layout & construction. There was a time later when the Weymouth factory realised they were repeatedly seeing alot of these amps and took to stripping them out & rebuilding them to the final & reliable spec even without being asked to by the customer and without charging for it (usually without telling the customer too!) It proved to be more cost effective to do that than spend time trouble shooting in each rat's nest only for the amp to fail again later. Many, many amps were thus re-built and have been subsequently trouble free. It was expensive to do it though.

[Spectral Morn]

HI Guy


Guy is right in what he says. There were reliability problems with early Series 500 and other AI kit too. I didn't want to say anything about that. The later 500 after my version did not sound as good in my opinion, they had much thinner metal work and only had two speaker output taps. I have not heard every version of the Series 500. I must say that the line only version of the 500, the Series 700 was also an amp I didn't like the sound off. There used to be guy called Dimitri based in Holland who had a site just for the series 500 but it would appear to be gone. Border Patrol is your best option for info now.


Regards D S D L----Neil

[Steve Toy]

Tip: remove those rings from around the valves - they kill dynamics!

[pure sound]

The 700 was the 800 Mk3 with source selection and vol & balance controls. But it didn't sound as nice as the 800Mk3 probably due to said controls & wiring. Funnily enough the Classic 25 (kit amp) was also broadly similar to the 700 but for some reason sounded much nicer. The 500 had metalwork from various places and on some of the earlier ones it was more like armour plate! The best 500 would be one with the original Hinchley mains and output transformers that had then been rebuilt leaving those parts alone. I imagine yours might be like that Neil. There are alot of those about.

[jrmanders]

Tip: remove those rings from around the valves - they kill dynamics!

I agree Steve, tried some EAT valve dampers on the valves inside my Puresound P10 and didn't like it one bit.

Seemed to go to dry for me.

Jonathan.

[Mike]

Tip: remove those rings from around the valves - they kill dynamics!

Bollock!