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Barry
14-09-2010, 22:09
Guys,

I need your advice. A friend of mine runs an Audio Innovations 500 integrated valve amplifier into a pair of Impulse H2 horn-loaded loudspeakers.

His amp has just gone pop; sounds serious - I suspect the primary transformer winding has gone open circuit. He's having the amp seen to at the moment, but has asked me to ask you to suggest a suitable solid-state replacement.

The AI 500 produces 15w/channel from a pair of EL34s. The Impulse H2 have a sensitivity of 94dB for 1 Watt. He is looking for a solid-state integrated replacement/back-up amplifier and wants to spend no more than £1,200.

Any ideas would be greatfully received.

Thanks

Regards

Dalek Supreme D L
14-09-2010, 22:28
Guys,

I need your advice. A friend of mine runs an Audio Innovations 500 integrated valve amplifier into a pair of Impulse H2 horn-loaded loudspeakers.

His amp has just gone pop; sounds serious - I suspect the primary transformer winding has gone open circuit. He's having the amp seen to at the moment, but has asked me to ask you to suggest a suitable solid-state replacement.

The AI 500 produces 15w/channel from a pair of EL34s. The Impulse H2 have a sensitivity of 94dB for 1 Watt. He is looking for a solid-state integrated replacement/back-up amplifier and wants to spend no more than £1,200.

Any ideas would be greatfully received.

Thanks

Regards

S/H Pathos Acoustics Classic One mk2 (don't touch the MK1 with a barge pole) the Mk3 is very good too but a tad brighter.

This is a beautiful valve hybrid of 75watts Class A. It will be a touch brighter and less full than the AI 500 but it is a fabulous amplifier and a firm fave of mine. It sounds better if used via its balanced XLR inputs over the RCAs. So if your friend has a CD player etc with a set of XLR outs (assuming its true balanced) he should use it this way. RCA inputs sound great as well just not as good as the XLR in.


http://www.ukd.co.uk/assets/_managed/editor/image/Classic%20One%20web.jpg
http://www.jordanacoustics.co.uk/php/resources/images/classic%20one%20b.jpg

A S/H Sugden A21se would be another option.


Regards D S D L

The Grand Wazoo
14-09-2010, 22:31
Barry,
Does the new amp need to have a phono stage?

Barry
14-09-2010, 22:44
Barry,
Does the new amp need to have a phono stage?

Strictly speaking yes. He has been gradually replacing his LPs with CDs, but there could well be some LPs he will not be able to replace, or at least not for some time. He plays vinyl rarely, via a Mitchel/Rega/Ortophon setup using an Hi-Fi News 'Black Head'(?) transformer.

He does not run a tuner and only records/plays cassettes once in a blue moon.

Can't really tell you what he wants from a system, save to say he's happy with what he has, but is looking for a transistorised replacement. He likes my system; says it's more detailed and has more clarity and impact than his, but does appreciate the much better extended bass his Impulse speakers achieve.

Regards

Barry
14-09-2010, 22:46
S/H Pathos Acoustics Classic One mk2 (don't touch the MK1 with a barge pole) the Mk3 is very good too but a tad brighter.

This is a beautiful valve hybrid of 75watts Class A. It will be a touch brighter and less full than the AI 500 but it is a fabulous amplifier and a firm fave of mine. It sounds better if used via its balanced XLR inputs over the RCAs. So if your friend has a CD player etc with a set of XLR outs (assuming its true balanced) he should use it this way. RCA inputs sound great as well just not as good as the XLR in.


http://www.ukd.co.uk/assets/_managed/editor/image/Classic%20One%20web.jpg
http://www.jordanacoustics.co.uk/php/resources/images/classic%20one%20b.jpg

A S/H Sugden A21se would be another option.


Regards D S D L

Thanks Neil,

but the amplifier has to be solid-state. The Sugden would fit the bill. I'll look at the spec. Any idea how much they fetch on the s/h market?

Regards

The Grand Wazoo
14-09-2010, 22:47
.........and is secondhand in the frame or must he have new?

The Grand Wazoo
14-09-2010, 22:48
I guess the answer to the 2nd hand question is yes then!
I was going to suggest a 2nd hand LFD.

Barry
14-09-2010, 22:53
.........and is secondhand in the frame or must he have new?

Would prefer new, but £1,200 is the absolute limit. Unfortuately he has been out of the Hi Fi loop for some years now, so probably doesn't realise how much stuff cost these days. For example he is also thinking of replacing his elderly CD transport for a newer one. Found an ex-demo Cambridge CD93, but balked at the ~ £400 being asked for it.

DSJR
15-09-2010, 09:17
The thing for me is - I found the AI500 rather thick and clogged sounding, as if a blanket had been thrown over the performers. There's no way a solid state amp will mimic this unless it's very sick indeed...

How about a Puresound A30 or, if he can stretch to it, a Croft Micro Basic with Series 7 power amp? I know the latter very well now and it is so good at what it does. Some tube-rolling might mellow it down a bit too (Mullard Long Plates perhaps?) to take the edge off the speakers.

For good used amps, Jimmy Hughes used DNM's for years (probably still does) and these drove the Impulse speakers he had to very high levels with no strain or stress at all. The sonic clarity on a good day could be breath-taking too.

Dave Hewitt
15-09-2010, 09:47
Hi
The dpa amps are supposed to be very good with the h2 speakers,not that expensive second hand.My own choice would be a pass f3.
Dave.

chris@panteg
15-09-2010, 11:01
Barry did state 'solid state' only

At £1200 price point , the Leema Pulse or Cambridge Audio 840A v2

chris@panteg
15-09-2010, 11:16
Oh and a bit of an afterthought the NVA A70 or A80

Richard Dunn is not the most popular chap on this forum , but he has an audience and quoting from Hans kellar 'anyone who has an audience ought to be heard'

Listen to them' then decide .

Barry
15-09-2010, 11:18
Barry did state 'solid state' only

At £1200 price point, the Leema Pulse or Cambridge Audio 840A v2

Thanks Chris,

The Cambridge Audio looks interesting. My friend used Arcam Delta CD transport and DAC. Are Arcam the same as Cambridge Audio?

Will have a look at the Leema Pulse. Being a conservative sort and, as I have said, having been out of the HI Fi loop for several years, he is unlikely to have heard of Leema and would want to know something of their track record. I remember André speaking well of them.

Apropos valve vs. solid-state, my friend has got it into his head that a solid-state amp will use less electricity and cost less to run. No doubt his AI amp can be repaired, but he specifically stated he was only interested in a solid state alternative and that £1200 was the absolute maximum he wanted to pay.

Jason P
15-09-2010, 11:33
Here's a leftfield suggestion, as he has very efficient speakers...

a pair of these (http://www.templeaudio.net/monoblock.html) with a nice passive preamp, and bob's yer uncle. or combine it with a Caiman and one of these (http://www.furutech.com/a2008/product2.asp?prodNo=374) for a complete solution that will cost next to nowt to run and still leave him with change from a grand.

Jason

JOE!BLOGGS
15-09-2010, 16:36
hi
get yourself a pair of hypex ucd modules, blow valve amps away including single ended triodes. just no contest!

joe

DSJR
15-09-2010, 17:11
Arcam is an abbreviation of A&R Cambridge. Cambridge Audio is and was a different entity altogether and I believe was started by Stan Curtis around forty years ago.

I forget about the 840A amps, but they are very powerful and power isn't necessarily what's needed here. maybe one of the smaller ones would be able and give little or nothing away in performance?

The Grand Wazoo
15-09-2010, 17:15
I bet that little old Electrocompaniet 20 watter that you mentioned elsewhere recently would be great into the Impulses Barry. What about a Muscal Fidelity A1 or something similar?

Barry
15-09-2010, 17:39
I bet that little old Electrocompaniet 20 watter that you mentioned elsewhere recently would be great into the Impulses Barry. What about a Muscal Fidelity A1 or something similar?

Good suggestions Chris, but it would mean tracking down good second-hand samples. It's the sort of thing that I would do, but my friend might need to be convinced of the reliability of either amp; both ran very hot. (Bolt two A1s together as a hinged pair and you've got yourself a hi-fi Breville sandwich toaster!)

Would also need to find a suitable preamp for the Elecrtocompaniet: it needs a pre- with a very low source impedance (< 10 Ohm), though I was assured by the then dealer for Electrocompaniet (Norse Ecosse) that the high level output of the Quad 44 (5V, 75Ohm) would work.

Thanks for the all suggestions so far, Guys, I'll compile a list for my friend, so he can assess the options. Any more suggestions? Keep 'em coming.

Regards

Barry
15-09-2010, 17:48
Here's a leftfield suggestion, as he has very efficient speakers...

a pair of these (http://www.templeaudio.net/monoblock.html) with a nice passive preamp, and bob's yer uncle. or combine it with a Caiman and one of these (http://www.furutech.com/a2008/product2.asp?prodNo=374) for a complete solution that will cost next to nowt to run and still leave him with change from a grand.

Jason

Interesting suggestion and worth considering. Do you know of an off-the-shelf passive pre, that can switch between two line level inputs (CD and cassette) and a moving coil phono? (I'm aware of the Music First, but that would saturate his budget).

Thanks

Marco
15-09-2010, 17:56
hi
get yourself a pair of hypex ucd modules, blow valve amps away including single ended triodes. just no contest!

joe

Lol - no comment!

Marco.

Labarum
15-09-2010, 18:15
Does amplification really have to cost so much?

MartinT
15-09-2010, 18:25
I would have said class A for those speakers, except for the need to use *less* electricity than valves? Sugden comes to mind, or a used Musical Fidelity A100.

Dave Hewitt
15-09-2010, 18:35
Hi
For what its worth hypex through h2 is about as bad as it gets.These speakers need an amp that is not lightweight or clinical sounding.I would use single ended tube amp or small class a transitor job,on second thoughts the Jungson class a amp would probably be a super match.
Dave.

Reid Malenfant
15-09-2010, 18:47
I would have said class A for those speakers, except for the need to use *less* electricity than valves? Sugden comes to mind, or a used Musical Fidelity A100.
Class A would be best obviously. The power requirements kind of kick that out unless it's small though as you implied.

How about a Musical Fidelity P150? I use these things myself & they are in no way harsh driving Yam NS1000 mid & tweeters. They can be had for very reasonable money & won't cost a fortune to run even though bias is fairly high due to the mosfet outputs.

Only bad thing about them is the PSU caps will likely need replacing :( As standard they are 63V caps, yet the rail voltage at idle is 67V :rolleyes: I might still have 8 x 80V caps here that are a straight swap & of the correct value. They are easy enough to get hold of though as they are snap in electrolytics.

Ali Tait
15-09-2010, 18:54
Hi
For what its worth hypex through h2 is about as bad as it gets.These speakers need an amp that is not lightweight or clinical sounding.I would use single ended tube amp or small class a transitor job,on second thoughts the Jungson class a amp would probably be a super match.
Dave.

Second Dave's earlier post suggesting DPA amps.I bought Jerry's pair of Enlightenment amps and they are very good indeed.His above suggestion of the Jungsson is a good one too I think.I'd also consider a Sugden too...

JOE!BLOGGS
15-09-2010, 18:55
dave
which ucd modules and power supply config did you use with these speakers, would be interesting to know.

joe

Dave Hewitt
15-09-2010, 19:26
Hi Joe
I got these modules when they first came out,I think they are ucd 180,they impressed me that much they are on a shelf in the garage. they are built into one case but have seperate power supplies,which I think uses 500 watt transformers and 15000uf per rail per channel.I realise that these are early models and newer ones may be better but ,I could never get involved in the music using these.Jerry borrowed these once and I think he wasof the same opinion.
Dave.

Barry
15-09-2010, 21:21
Hi Guys,

My friend has just phoned me to say his AI 500 amp has been fixed. Was vauge about the fault, so have told him to find out exactly what the fault was, so as to report here.

The pressure is now off for the time being, but he is still interested in a solid state alternative. I think we now have plenty of useful and interesting suggestions, so I'll compile a list for him to consider.

Thanks to everyone for their interest and help - this is what makes the AoS forum such a good place to be part of.

Regards

The Grand Wazoo
15-09-2010, 21:25
Let us know what he does will you Barry?

Barry
16-09-2010, 21:16
Hi Guys,

Thought you might be interested in the sorce of the fault on my friend's Audio Innovations 500 integrated amp. Apparantly the bridge rectifier developed a partial short and was putting AC onto the DC HT. It was this that caused the fuse to blow.

Althouh the panic is over, he is still interested in a suitable transistor alternative and thanks to you I have the following list of candidates to run past him:

Sugden A21 Se
Sugden A48
DNM
DPA
Leema Pulse
Cambridge Audio 840a v2
NVA A70 or A80
Electrocompaniet (20watt)
Musical Fidelity A1
Musical Fidelity A100
TOCA SECA 20
Naim NAIT 5i

Of these he is most interested in either the Musical Fidelity or Naim NAIT. The TOCA remains a very attractive proposition but my friend would prefer an integrated item. (He like things to be simple.)

Thanks to all those who suggested various class T amp modules (Hypex etc.), but anything that would require the use of a soldering iron is not for him, even though I could do the soldering for him.

Chris (TGW) has kindly sent me the web address for Big Ears Audio, who have a few of the above mentioned amps on offer for reasonable prices, including the TOCA.

So again thanks everyone for your interest, help and suggestions. Once again, AoS has come up trumps.

Thanks

Regards

Mart
17-09-2010, 00:16
If he's thinking of going for Naim, I would say a NAC72/NAP140 combo would smoke the Nait and cost not a lot more and take no more space than an integrated too.

I'd also recommend a Denson Beat 100 integrated.

For pics n specs:

http://www.soundscapehifi.com/used-densen-beat-b100-005.htm

Clive
17-09-2010, 08:06
Sugden A21 Se
Sugden A48
DNM
DPA
Leema Pulse
Cambridge Audio 840a v2
NVA A70 or A80
Electrocompaniet (20watt)
Musical Fidelity A1
Musical Fidelity A100
TOCA SECA 20
Naim NAIT 5i

Just some random thoughts....

Naim, even a modern one, with his speakers? I'm not convinced that's a good match.

The MF A1 and A100 could work well but given the heat inside those amps they will need re-capping, I mistrust reliability of those amps as they are rather old now and run very hot internally. The volume controls tend to need replacing too.

20W solidstate watts are probably ok, 30W might just give a little extra headroom. Having said that the Sugdens should be a nice match, I know the the A21 is good with 100db OBs.

DSJR
17-09-2010, 08:16
If he's thinking of going for Naim, I would say a NAC72/NAP140 combo would smoke the Nait and cost not a lot more and take no more space than an integrated too.

I'd also recommend a Denson Beat 100 integrated.

For pics n specs:

http://www.soundscapehifi.com/used-densen-beat-b100-005.htm

I agree about the Densen, with slight reservations about servicability later on...

As for Naim, have you ever compared a 140 with a Nait5i? The current Naim "sound" isn't as harsh and fatiguing as it was post 1980 and I even think the Naits now have a Zobel network on the amp outputs, possibly to enable real world use rather than the closeted one enjoyed by the upper-caste models. Used with very sensitive speakers, a Nait 5 of any era would never be stretched enough to clip and I would say from personal experience that the sound is very good with bags of subtlety until clipping is reached, at which point it HURTS!!!!!!!

The NAP140 was a dog of an amp through most of its life, as was the NAP110 through ALL of its tenure in the range. Hard toned, even harsh on occasion with no spatial perspectives but shedloads of prat, this power amp couldn't be further from an AI500 if it tried................. A Nait 1 or even the more capable Nait 2 was a FAR more pleasurable listen - and this was to new ones.......

Ali Tait
17-09-2010, 10:04
Barry,will your friend consider a tripath amp? If so,the Hlly t-amp 90 is very good for not a lot of money.Very cheap to run too,being extremely efficient.

Mart
17-09-2010, 21:31
The NAP140 was a dog of an amp through most of its life, as was the NAP110 through ALL of its tenure in the range. Hard toned, even harsh on occasion with no spatial perspectives but shedloads of prat, this power amp couldn't be further from an AI500 if it tried................. A Nait 1 or even the more capable Nait 2 was a FAR more pleasurable listen - and this was to new ones.......


Agreed if your talking about the chrome bumper, the olive version was a different kettle of fish though.

Personally, the Naim sound isn't for me, even with their latest offerings and though I think the styling on the new stuff is appealing to the eye, I don't like the way the rattle when you give them a gentle shake.

As for the Denson, I'm thinking of picking up another one to play with, as you do, cracking amps.

DSJR
18-09-2010, 09:35
I sold Naim from 1977 right through to 2004 and can tell you that whether in the shop - OR AT NAIM HQ - the 140 was the weakest amp they made by far in sound, followed closely by the 250 for some strange reason. The nait 2 and 135's were on a different sonic plane - and this was driving Kans (at Naim), which have a very easy load..

Towards the end of the Olive era, we re-located to the depths of East Northants and I went to work in Northampton. I must admit the 140 sounded more civilised by this time and I believe the output transistors were upgraded around the time of the 180's introduction, our 6 month old 250 having to be returned to the factory as it sounded inferior to the 180. It came back much better.

Apologies for the thread cr@p. Vintage naims of any age over ten years will need fettling now and I should say that once done, they usually perform better than they did when made. I think the Avondale mods are more for me than the Teddy ones, but have no need to try them currently.

Rare Bird
18-09-2010, 10:22
Stemfoort SF100

retro
18-09-2010, 11:46
I think Neil nailed it in second post.Pathos clasic one mkII would be the primary amplifier, and not back up.It is so good for sensitive speakers.
I heard him with a WLM Diva speakers (97 dB).Worth to try Barry.
Although not completely SS your friend could change his mind, unless it has a problem with the look of the amplifier.
Secondhand here costs about 800 pounds.

regards,

Mart
18-09-2010, 18:09
I sold Naim from 1977 right through to 2004 and can tell you that whether in the shop - OR AT NAIM HQ - the 140 was the weakest amp they made by far in sound, followed closely by the 250 for some strange reason. The nait 2 and 135's were on a different sonic plane - and this was driving Kans (at Naim), which have a very easy load..

Towards the end of the Olive era, we re-located to the depths of East Northants and I went to work in Northampton. I must admit the 140 sounded more civilised by this time and I believe the output transistors were upgraded around the time of the 180's introduction, our 6 month old 250 having to be returned to the factory as it sounded inferior to the 180. It came back much better.

Apologies for the thread cr@p. Vintage naims of any age over ten years will need fettling now and I should say that once done, they usually perform better than they did when made. I think the Avondale mods are more for me than the Teddy ones, but have no need to try them currently.


Weird innit ?

When you think about slightly older Naim products the first thing that springs to mind is "Ooh, hmm, that'll need a service".


But we digress.

Back on topic:

Theres a lovely Quad 909 FS in the classifieds over on the Wam :idea:

DSJR
18-09-2010, 22:12
When you think about slightly older Naim products the first thing that springs to mind is "Ooh, hmm, that'll need a service".


But we digress.



:lolsign:

:eyebrows: