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Vintage amplifiers that could challenge or approach current state of the art amplifiers

Ken Tajalli

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Hope these are readable - I'm no photographer and the phone although good for general snapshots, may not be up to this kind of work - Look at the distortion figures though - they'd resoundly fail if tested at this level here today...

Thank you very much, very interesting.
It seems that the 103, 103D have similar distortion levels, I wonder if the bias was set correctly!?
I did tinker with these amps a fair amount at the time, and if the bias is not set high enough, then crossover distortion sets in, it will sound bright and gritty.
I also think a fair amount of the distortions is due to the preamp. I never liked it, though it was nice, but it was the bottle neck.
The rather high output impedance, also meant not every speaker was suitable.
I really have very fond memories of the 103Ds and not the 103s. For years, the 103Ds were my choice of amp. I think once a 105 failed, and Meridian repaired it free of charge, I believe they were 15 years old at the time!
 

Steven Holt

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1971/2/3.

Here's some details:


and here lots of details and historic pictures:

The most beautiful one IMO is this in HP colours:

View attachment 244543

Thank you for the information, will read the links in detail. The one pictured is indeed lovely, I take it that it's meant to be rack - mounted? And yes, 1971. Makes sense.
 

Steven Holt

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Thank you for the information, will read the links in detail. The one pictured is indeed lovely, I take it that it's meant to be rack - mounted? And yes, 1971. Makes sense.
The more I read, the more amazed -- 'a very msuical and involving amp with excellent dynamics and no listener fatigue' 'clarity is astonishing' 'made by the employees in their off hours'. If this isn't evidence of ' the golden age of audio', then I don't know what is. Many thanks!
 

MAB

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Thank you for the information, will read the links in detail. The one pictured is indeed lovely, I take it that it's meant to be rack - mounted? And yes, 1971. Makes sense.
It looks like the amp is built into HP's standard modular chassis of that era, and it looks like a standard set of HP rack ears would fit. Here is a half-rack width version of the same general chassis from the late '70s, it's a sweet design. I kitbash DIY stuff into those old chassis for the same reason that HP built them in the first place!
1668968365454.jpeg
 

Doodski

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It looks like the amp is built into HP's standard modular chassis of that era, and it looks like a standard set of HP rack ears would fit. Here is a half-rack width version of the same general chassis from the late '70s, it's a sweet design. I kitbash DIY stuff into those old chassis for the same reason that HP built them in the first place!
View attachment 244734
Yeah and color matched spray paint is available for those. Very nice.
 
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Doodski

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This was my "standard" amplifier, a small-lot production series 13 years ago. 2x330W/4ohm, all of them still working well. $2600/pc from myself directly, $4700/pc from distributor's High-End shop. Discontinued now.

View attachment 244793
O' nice & dual mono à la dual transformers. What are those 2 green PCBs that are attached to the rear panel for?
 

jsrtheta

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They are an excellent preamplifier with little to criticise about the design. What I love about them is the complete left/right separate power supplies right back to the transformer and very careful layout.

The ALPs bowden cable linked switches can get noisy/intermittent in their old age and it is a big job to properly fix. (I'll post up a link to yesterday's rainy day Rotel project).

Enjoy. :)
Please do. Rotel has never failed me.
 

Mudjock

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I would be curious how the Citation 7.1 would measure up. It seems to have been designed to some very ambitious requirements.
 
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restorer-john

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Theres a few on Ebay right now.

Thanks for the heads-up. :)

There's often plenty of Japanese home market 100V units for sale. They must have sold a lot in Japan, that's for sure.

But I want a 220/240V unit and they go for big money. And I don't really need it. I have two of the smaller brother- the POA-1500bk.
 

tubess1988

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Thanks for the heads-up. :)

There's often plenty of Japanese home market 100V units for sale. They must have sold a lot in Japan, that's for sure.

But I want a 220/240V unit and they go for big money. And I don't really need it. I have two of the smaller brother- the POA-1500bk.
Ah ha..did not take the time to see there were from Japan, will a100 Volt model work on a USA 120V line?
 

pseudoid

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Weren't there some So.Korean audio manufacturers which were trying to create a rivalry with Japanese audio manufacturers, circa '90s?
Their similar rivalry succeeded w/Kia/Hyundai brigade stealing much market-share from the Japan (et al.) auto industry.
Firestone was one such brand.
 
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restorer-john

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Ah ha..did not take the time to see there were from Japan, will a100 Volt model work on a USA 120V line?
Not without a very large stepdown transformer. Personally, I always prefer a correctly wound transformer or a multitapped, multivoltage unit.

Big power amplifiers rarely perform well when sitting behind stepdown transformers in my experience.
 

mhardy6647

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OK. We were on the way out with the brand by the time of the 500's, but I remember two samples of 506 CD player made several months apart heard fairly close to each other using similar gear and comparisons and one sounded dull and the other thin toned (this kind of thing happened in the subjective-only days of the late 90's). Mid period Linn Karik CD players were the same, the motherboards changed a few times in the mid 90's and results at the time I judged quite audible. The 502 'balanced' preamp was a delight and didn't change and the 501 RCA-only model wasn't so good in reproduction of reverb/acoustic, but it had a revision (not sure if it became a full mk2) and that sorted it out.

The thing is today, with a far more objective bent, it's easy to dismiss these subjective findings as nonsense and imagined and I can't dispute that at all. But I can think of a handful of UK makers back then who did seem to design and somehow 'voice' their products to get good subjective reviews. All this time, there were mid priced CD players by Denon for example, which held to pretty much neutrality (and have stayed the course because of it) and my preamp reference then was the Bryston BP25 (which I still maintain needed some hours after a cold start before fully settling down subjectively - my experience and opinion and I'm damned well sticking to it, so there! :D )


As for seriously good vintage amps which may compare well today, it's difficult. Bryston was mentioned earlier and I feel the 70's Crown/Amcron amps should be considered as well. Ken Rockwell has measured a few and 4 ohm loads apart (when protection can kick in), they're not bad at all still for fifty year old designs. I remain delighted with my inherited pile (IC-150's lightly serviced, D-60's and a cheap D-150 which needs the optional front panel to dress it up) and they seem 'honest' enough for my needs as my speakers don't dip below 6 ohms. Here's my actual power amp in all it's flaking paint glory from the ad. DC offsets well within spec and I haven't tinkered.

View attachment 244562 View attachment 244563
looks like the backside of a D-150 to me...

Here's the frontside. :)
Mine were dump finds (which I've certainly mentioned before). Predictably working fine as found.

 

DavidMcRoy

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My list of "owned" and "still owned" amplifiers will contain familiar ones that's have shown up here. I have a thing for FETs and MOSFETs, as you can see:

Hafler DH200
B&K ST-140
Adcom GFA-535
Adcom GFA-555
Hafler PRO2400
Hafler P3000 TransNova

A couple I haven't seen here:

Rotel RMB-100 Monoblocks (MOSFETs)
Rowland Research/Jeff Rowland Design Group Model 7 Monoblocks

The Rowlands were just taken out of long term storage in Florida and are being moved here to the state of Washington. They were a gift from a former employer and I haven't heard them in many years.
 
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pseudoid

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looks like the backside of a D-150 to me...

Here's the frontside. :)
Mine were dump finds (which I've certainly mentioned before). Predictably working fine as found.

These Crowns had the look of HeatKits on steroids but I don't think 'steroids' were invented yet!;)
 
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