New Amps for Old

of course you will, it still looks mint and good looking nostalgic amp, like a vintage car, full of personality,
 
Dev said:
I'll have to borrow it sometime:)
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Hi Dev,

I have your Luxman here and working very well.

Other than some mains suppression which might help you interference issue it needed nothing doing.
Bias, offsets and voltages are all checked and within spec.
 
On the issue of older amps working well with digital, as has been mentioned, good digital isn't an issue at all. But you could argue that some older kit is better placed to deal with less than clean digital sources as those amps tended to reduce gain outside of the 20-20k window more aggressively than many modern amplifiers.

HF noise isn't some new phenomenon ushered in with the digital age. Disc cutter head ringing has been with us for decades, and anyone who has worked on FM tuners will know that proper suppression of the HF carrier and multiplex (38kHz) wasn't always done correctly - sometimes not at all!

There is an argument that filtering is bad but I see no credible arguments for this, other than purely subjective comments from those selling wide open amplifiers.
I'm not saying you should brick-wall everything at 20kHz but it makes sense to start reducing gain thereafter and steepen the filter slope once you get past 30kHz.
This used to be the norm back when audio was predominantly built by engineers rather than those building according to some fanciful notion. The idea that removing all filtering* somehow gives a cleaner window is nonsense. What it does is make your nice clean window incredibly sticky and a magnet for passing crud.

So you can argue that a Quad, Naim, Sugden or Exposure amplifier is better placed to deal with a dirty signal than many others.


*All amplifiers filter to some degree and there is no such thing as wide open amplifier. The minute you introduce an interface - any interface - you create a filter.
 
A 33 and 405 have just come out of the wardrobe and gone back into use in my second system (after an olde Exposure VIII blew a channel). In all honesty they're some distance off my main rig in terms of sound performance. However they refuse to die, and visitors marvel at the sound compared to whatever shiny things they sell in Comet / Currys nowadays. Plus the looks are iconic.

Pete
 
33 isn't suited well to modern sources as there is far too much gain.
All inputs are set to 100mv sensitivity which is not only far too high today but will likely clip with many sources.

A 405 with a service is perfectly fine though.
Input sensitivity is 0.5v for use with Quad pre amps but you can reduce this easily by swapping two resistors and one cap on each board. The cap change is needed to preserve the high pass filter knee.
Did this to my 405/2 recently reducing sensitivity to 1.5v and similarly reducing the output padding on the 34 pre to increase that to the same level.
Net 10dB improvement in noise performance, and improved distortion performance from the 405 as there is now less gain at the front end.
 
Labarum said:
I bought my 405-2 a couple of years ago on eBay at a good price and had it re-furbished by 405man who sells refurbished 405s on eBay.

He replaced the power supply and a few other critical caps and he changed the controlling op-amp for a more modern one.

He promised me an amp "as transparent" as all but the very best modern amps.

I have certainly not been disappointed. The 405 and other Quad amps are, I guess, the foremost example of keeping good stuff in use, and even making improvements. Net Audio and other firm support these principles.

What does the membership think about keeping these veteran amps going in preference to spending on brand new kit?

I have heard it said that the modern amps can measure better than the best of the old, and the old designs don't handle so well the vestiges of RF noise that digital sources can squirt into them. I have not found the refurbished Quad wanting on either count.

Where do folk think the balance of advantage rests, with the new-for-old, or with the sparkling brand new?
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I'm a big fan of old amps. I'm of the opinion that amps are the one area where nothing much has improved over the last 20 or 30 years. I'm sure that new amps may measure better, but can the difference be heard? I'm not sure.

There's a lot of talk about equipment ageing but, again, I think this is overplayed and an amp used in a domestic environment should easily last 30 years if it hasn't been abused.

I got myself a Pioneer A400 for 70 quid as I though it was worth a punt and it's been in my main system now for 6 months and I'm not planning on changing it any time soon.
 
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RobHolt said:
The circuit in the B200 is excellent - TdP at his best IMO.

It uses a high speed op amp at its heart and literally a handful of parts per channel. Simple and very good indeed.

I recently rebuilt a P170 power amplifier which uses the same Mosfet circuit but with a much larger dual mono PSU. Superb amplifier though truly poor build quality - much improved these days.

Must pick up a nice B200 for my collection.
P140 and Pre 3a are also great and effectively a B200 split into two cases.
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I just brought down my B200 from a freezing attic last night, and am currently letting it aquire room temperature before switching it on, it's going to replace my TPX'd Supernait and Lavardin IS :eek: whilst I search for a pre to mate a Linx Vega (latter in the realms of the snow-delayed delivery people). Any suggestions for a pre for the Linx BTW?
 
i will never get rid of this B200, it is as you said Rob, in a few words an "ICON"even going now trough my tannoys it sounds so good that is incognito until i realise that the lovely sound is coming from that simple looking amp,
 
Hi Nando

As someone who has been somewhat apathetic towards MF's early-ish products (I have owned a few), listening afresh to the B200 is a turning out to be a real eye-opener. It is lively, clear and a better match for my Shahinians than I would have imagined. Even though this sample is over 20 years old (maybe it doesn't measure well as it did when new), it is definitely not embarrassed in following the Supernait and Lavardin.

My Linx Vega arrived today, but am enjoying the B200 too much to be bothered to swap over!

Rana
 
Rana said:
Hi Nando

As someone who has been somewhat apathetic towards MF's early-ish products (I have owned a few), listening afresh to the B200 is a turning out to be a real eye-opener. It is lively, clear and a better match for my Shahinians than I would have imagined. Even though this sample is over 20 years old (maybe it doesn't measure well as it did when new), it is definitely not embarrassed in following the Supernait and Lavardin.

My Linx Vega arrived today, but am enjoying the B200 too much to be bothered to swap over!

Rana
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Should be easy and inexpensive to service if anything has drifted. The circuit is remarkably simple and very effective.
 

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