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Post by Chris on Mar 28, 2016 6:02:03 GMT
I've noticed a few amps with point to point wiring and this seems a desirable feature. Could someone please explain the benefits or why this is done.
To me it suggests a handmade article and I much prefer the look. Bet there's more to it than that though....
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Post by AlanS on Mar 28, 2016 7:03:47 GMT
Point to point I thought was a horse sporting activity.
Never heard of it in amplifier world, you open my mind. I thought the quality of connections and wire make the largest difference, thats what the guy who serviced my amp said.
Perhaps it is to contrast with printed circuit designs which are a bit massed produced.
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Post by Chris on Mar 28, 2016 7:30:24 GMT
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Post by Deleted on Mar 28, 2016 7:42:16 GMT
I thought the benefits were to do with a wire carrying the signal rather than a solder track. A bit like comparing a hard wired passive with a cheapie using a PCB. Presumably less chance of signal loss.
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Post by AlanS on Mar 28, 2016 8:45:42 GMT
Ah good old valve amps rich in sound. I thought all valve amps were wired due to the voltages involved. Sounds like a sales term |
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Post by Chris on Mar 28, 2016 9:04:51 GMT
No mate quite a few use circuit boards. I have heard of one company who says that pcbs aren't as good but I'm not sure.
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Post by Deleted on Mar 28, 2016 9:08:28 GMT
Have a look at Audion's webpages Chris. They have a downloads section with info on point to point wiring as far as I can recall. Graeme is a believer and produces PCB and point to pint versions of his amps. The latter at a premium. I can't argue as his amps sound wonderful to me, as long as you partner them sympathetically. www.audion.co.uk/products.html |
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Post by pre65 on Mar 28, 2016 10:12:10 GMT
PCBs are good for fit and forget circuits, and probably for things like phono stages where layout and short signal paths are vitally important.
Point to point wiring, and tag boards are wonderful for DIY or low volume kit, and almost essential for inveterate component swappers. 
The only PCBs I use on my valve amps are for "esoteric" filament supplies, which do make a worthwhile improvement.
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Post by Deleted on Mar 29, 2016 8:42:24 GMT
Audio Research have always used PCB's, and I've not heard anyone moan about the audio credentials of those.
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Post by MartinT on Mar 29, 2016 8:50:45 GMT
I think the PCB versus point-to-point arguments just run and run. And, of course, PCBs are not all the same, some vendors using very expensive materials.
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Post by ChrisB on Mar 29, 2016 9:17:17 GMT
Audio Research have always used PCB's, and I've not heard anyone moan about the audio credentials of those. I have. (ARC owner here!) |
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Post by Deleted on Mar 29, 2016 9:58:49 GMT
I think the PCB versus point-to-point arguments just run and run. And, of course, PCBs are not all the same, some vendors using very expensive materials. Well, yes indeed. The standard is FR4, which is good to the hundreds of MHz and is easy to multilayer. Judging by what I see in Audio Research gear, they use FR4. There are a variety of more esoteric materials based on PTFE, ceramic loaded PTFE and various other hydrocarbons if you want to get deep into the GHz range. Problem is in multilayering with PTFE (two layers typical max), so if you want buried power and ground it is much more difficult. The most esoteric stuff I have used is for space instrumentation. Because of the outrageous temperature range it is important to chose a material that matches the CTE of space qualified surface mount/gull wing devices so the device or solder joints don't crack. Whatever it was I specified it was made by one of these escies.org/webdocument/showArticle?id=217&groupid=6 . For space use you can have no top or bottom tracks, and everything has to be buried. In addition you need a thermal control layer - no convection cooling in space. So everything that dissipates much at all is thermally tied to this layer and conducts to the chassis (and then via ammonia heat pipes to the radiator panel which faces deep space). Also no silk screen or solder resist is allowed (for outgassing and long term degradation via radiation exposure). That makes soldering and component placement a real challenge. That PCB was ten layer, with things like a 500-pin gullwing FPGA at £20k a pop for full space qual parts. Times 4. Just for starters - the electronic rule of thumb is think of commercial part prices and add three (and often four) zeroes. On point to point for audio gear (back on topic), that is fine and dandy for DIY and for very low volume esoterica. But anything that is made in any kind of volume absolutely needs a PCB of some sort. |
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Post by MartinT on Mar 29, 2016 11:04:29 GMT
Indeed, I can't imagine Stan manufacturing the Caiman-II as point to point build at its price point, simply not possible.
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Post by Chris on Mar 29, 2016 11:20:51 GMT
Very interesting answers. Much appreciated gents.
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Post by Deleted on Mar 30, 2016 15:25:26 GMT
Here's a period example of the cost of point to point wiring, in the pre-pcb era. Quad advert from 1951 www.meridian-audio.info/public/quad-ww-dec-1951%5b3259%5d.pdf . Remember this is mono, so the cost of the preamp, power amp and speaker should be doubled to get £236. The average annual income in 1951 was £200. So the cost of a point-to-point wired Quad (stereo) was more than the average annual salary. Scaled up for the change in RPI (29x) gives a price in today's money of £6.8k. Or if you scale it to the annual average salary of £17,600 - £20k. Another good example of point to point wiring from the same era are Tektronix oscilloscopes. In 1951 the type 517 was USD3500. The exchange rate was about 0.35, so say £1k in the UK, five times average salary, and more expensive than a three bedroom semi (£750). |
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Post by Chris on Mar 30, 2016 15:42:24 GMT
Good Lord!!
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Post by Deleted on Mar 30, 2016 17:22:07 GMT
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Post by dsjr on Mar 30, 2016 20:30:08 GMT
Audio Research have always used PCB's, and I've not heard anyone moan about the audio credentials of those. You've not heard me then Nothing to do with the use of PCB's though, just deliberate design to offer an 'improvement' edition eighteen months after initial launch..... |
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Post by Paul Barker on Apr 10, 2016 8:57:51 GMT
That eBay example of point to point isn't the best. Because it is too neat looking, too many of the cable runs are bundled. The ideal is to only have separate runs crossing each other, not bundled together.
Pcb's are superior in the sense of economy, and pretty good sounding. Not a deal breaker to go pcb.
But if building point to point. Best to do just that go straight from point to point only crossing other wires not running together with them.
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Post by pre65 on Apr 10, 2016 9:25:22 GMT
One V8 engined car I had (Might have been the Sunbeam Tiger) one HT lead had to be specially routed as it induced a voltage in another lead that was close in firing order.
So neat wiring is not always good. 
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