TDA2030A Audio Amp

Back in the day when I worked for BBC Engineering the almost universal loudspeaker amplifier was a Quad 405, usually in bi-amp configuration. It was the amp of choice because, in the late Peter Walker's maxim the ideal amp was a piece of wire with gain, and it was solidly built and wholly reliable, day after day after day. Very little else originally designed for the consumer market has come anywhere near, my own example some 25 years old still outperforms most things on the market. Valve amps are just a pain, certainly in the wallet as revalving on a regular basis is essential, but unless you've got a high efficiency speaker design, horn loaded for preference, then they invariably have insufficient welly. Of course if your seduced by the hi-fi gurus, may you enjoy the dubious statements of betterment at your own considerable expense.

Regards

Martin

Edited By Martin Shaw 1 on 13/02/2018 21:05:43

What I would really like is a house that was big enough to house a pair of Quad ELS's

The most realistic sound I ever heard was in a hi-fi shop in Southport, probably in the early '70s, when my ears were young enough to appreciate it.

I can't remember the signal source, but the speakers were stacked Quad electrostatics (the original ones), two per channel, one above the other, driven by Quad valve amps. Crystal clear orchestral music that was quite mesmerising, even though I didn't appreciate "Classical" music then.

Hi Gents, split bobbin transformers tick all the boxes for the H&S brigade in terms of leakage pri/sec etc BUT, they have much worse regulation and higher losses, which could, with a poorly designed power supply increase distortion.

A correctly designed "sec over pri" transformer (earth screen and correct creepage and clearances) will give much better performance, use less total power and still be safe.

Note that the split bobbin design is virtually never used for the "holy grail" ~ output transformers.

Ed

Probably did. I agree that Tandy speakers were rubbish but don't you think that the size of enclosure you were in had something to do with it? Add in the ambient noise from a Mondeo engine and I doubt you could hear the distortion!

Quad electrostatics were excellent. They had diaphragms with a large area and very small excursion but needed a big room as they had to be sited well away from a wall for best results.

I like your KEFs. I seem to remember that Rogers used KEF drivers in their speakers.

Russell

I had a couple of ESLs, the original version, one made in 1957 the other in 1963. Probably spent over £2000 having them serviced, once by Quad the second by "onething audio", but last year the treble panels went again, so popped them on eBay and sold to an enthusiast who reconditions them himself. Now got a pair of Quad 21s which to my ageing ears sound excellent, though the ESLs when they were working properly were fantastic.

Bear in mind (1) I'd never wound a transformer before (or since) (2) it was the only type of kit Radiospares sold...

Fully regulated supply rails and caps the size of beer bottles (well not quite)

Edited By Neil Wyatt on 14/02/2018 09:55:20

Haven't seen electrostatics for >30 years. I saw one speaker that had a small electrostatic tweeter run off the valve O/P line before the impedance matching transformer.

Reminded of a man I was talking to a few weeks ago-- He asked me if I knew where to get lead shot. He needed it for some sound system he was building, had to pour the shot into the speaker stacks to get balance. he then went into his set -up at great length, most of which I didn't understand, his amp etc. etc. Turns out he lived in a 12ft caravan.

My Quad ESL57's still are, excellent that is. They knock most everything else into a cocked hat. Just don't overdrive them playing Heavy Rock, there is no real need anyway as they are the only speaker I have found that the word "immersive" really applies to. You just need to be selective as to which amp you use to drive them.

The most asinine comment I ever read on any forum anywhere with regard to "Hi-Fi" was a moderator claiming he could tell the difference in the positioning of the fuse in the supply cable to an amplifier by ear alone. It pretty much did for me with Hi-Fi and the bullshit surrounding some of the "accessories". I remember reading about one of Peter Walker's demonstrations (he of QUAD fame) when he discovered he had forgotten the mains lead and went over to a power tool manufacturer's outlet and bought a length of Electric Lawnmower cable to connect the Amps up with. Works for me.

Had supper with the 'big cheese' of a Bangkok import/export company back in the 60s. His hifi was a Ferrograph deck into a Quad pre-amp, Quad amp and a pair of Quad electro-statics. Had never heard of the latter previously but was much impressed -. He then put on a Florence Foster Jenkins recording and asked what we thought of it!! Never previously heard of her either!! Get out of that without embarrassment, then

Became quite interested in the quest for 'super-sound' (reinforced concrete window seat speakers etc.!!) until one of the more cynical critics pointed out that the ONLY way to get REPEATABLE sound quality of ANY sort was via headphones, as any other output would inevitably be affected by position, room contents, curtains etc. That observation has saved me a considerable amount of cash over the years

rgds

Bill

Mark,

I have a pair of ELS and the lounge is just the "right length" for good results!!!

About 10 years ago when I was doing a lot of hybrid vehicle work in Korea for Mobis (electrical compt division of Hyundai), I had a tour of their brand new R&D centre just outside Seoul where our customer team was based. This place was simply staggering, with whole vehicle EMC chambers and audio anechoic chambers ("vehicle" as in HGV). Amongst other things, they developed car audio systems there and demonstrated their audio refenece system to us visitors.

The autitorium was the size of a typical cinema with controllable wall coverings etc and the multiple speaker stacks would have been big enough to climb inside. There was also a large screen for video and they played some Eagles live tracks for us. The sound was simply stunning and I've never come close to experiencing anything since. The recordings weren't simple CDs apparently but even so, they were doing something very special, not least in terms of the financial investment involved. Nothing to do with gold plated knobs or directional cable woo science, simply technical excellence on a vast scale. And of course, not a valve in sight (sound?).

Personally, I simply make do with a miniature run of the mill Class D amp from banggood (CSR8630 chipset - single chip Bluetooth audio ROM platform and TI TPA3116 Class D output) and run 320k MP3 files from my NAS - pretty crappy I suppose but years of self abuse have taken care of any need for further improvement.

Murray

Edited By Roderick Jenkins on 14/02/2018 14:25:23

You might like to browse the results from Bellmans Winchester (uk) sale on December 12th 2017 - lots 539 plus

http://bellmans.co.uk/sales/winchester-sales/wdec2017/?page=21#sale-lots

and see what you missed. Don't look at the early lots from this sale unless you have a taste for the seriously politically incorrect!

Niall

It's a bit spooky that this topic came when I was clearing out the loft (orders from er indoors). I found WWs from 69 to 81 and reread all the Hi Fi articles and pro and cons of the Semi vs Valves and does current dumping really make a difference! Lots of good articles from Linsey-Hood et al.

Found a car radio I made from an RTV kit and the Dolby Noise Reducer (unfinished). I will see if the radio is still working.

Next task is to get a KEF B139 to repair my Cambridge audio R40s.

I have just refoamed my AR7 speakers and very pleased with the results. I got them from speaker-repairs.co.uk

Hugh

The BS got too much for me when I read in two articles in the same issue of one of the mags that:

(1) If you remove the 'power on' LED from the Linn power supply which powers the motor of your Linn turntable that you can hear the difference, and

(2) That the colour of the insulation on your interconnect wires makes a difference to the sound.

I stopped buying the magazines at that point.

Jez.

(Grey is best, in case you were wondering...)

I agree Jez... I frequently rolled about laughing when these audiophiles started talking about the good effect of ‘oxygen free copper’ speaker cable! I had a practical approach to HiFi making my own Lindsey Hood class A amplifier and home brew preamp and ‘tone contol’. Happy days!

The CD had to make compromises in sample rate and bits to get a normal album to fit on a CD. Although they sound good to me and to get away from vinyl and all the baggage that goes with it was a relief. A medium that only provides part of the story is going to struggle to deserve to be called hifi. The fact that formats like SACD didn't catch on and the extremely compromised MP3 is huge must mean that most people aren't too bothered about hifi. I feel that the media available will always be a limiting factor whatever system you put it through. Although many people have a love of vinyl I don't believe that it can record all the information that is produced by a live performance especially as a tape or digital recording usually sits in the middle as well as microphones. Although we may fool our ears that they are hearing a live performance Logic will tell us that it cannot be true. If you want hifi go to a concert or gig.

Mike

Edited By Mike Poole on 14/02/2018 20:05:47