Progression?

[Marco]

That's fair enough, Ali. All I can say is that in my experience I've yet to hear a truly outstanding sounding (by my standards) valve amp that uses PSBs.

I wonder why Glenn Croft insists on using point-to-point wiring in all his designs, even his £350 entry-level preamp (I don't believe there are any excessively high voltages in there, which kind of makes Mark's point somewhat moot), when he could save a whole load of time (and money) otherwise?

I've asked Anthony for his views on the matter, so that should make interesting reading when he comments in due course

Marco.

[Ali Tait]

Yes indeed.Perhaps Nick may comment also.I do agree that a lot of cheaper pcb's may well degrade sound,but good quality ones would I think be just as good.High quality ones would not be cheap though.

[Steve Eddy]

Also take the example of a single transistor input stage that I mentioned above. Old designs utilised it because it was the only option. Then differential input (two transistor) topology came about.

Naah. Differential topologies had been around well before the introduction of the transistor and those same topologies work for transistors just as they do for tubes.

If an input stage used just one transistor it was for one reason; to save money.

se

[Marco]

Yes indeed.Perhaps Nick may comment also.I do agree that a lot of cheaper pcb's may well degrade sound,but good quality ones would I think be just as good.High quality ones would not be cheap though.

Yup, and how often do you think high quality ones of the requisite standard you're talking about are used inside in any way affordable commercially produced valve amps?

There's no way that sort of cost could be factored into the budget and for the retail price to remain affordable. Genuinely hi-end commercial designs (say at least over £5k) might be a different matter.

Therefore, what's generally used in mass-market valve equipment is anything but high quality PCBs, with the resulting inevitable sonic penalties. This is precisely why Glenn Croft does what he does!!

Progress? No chance. It's yet another valid example of convenience over quality in today's equipment designs. I'll cite plenty more later!

Marco.

[Steve Eddy]

Solder is a necesary evil, having PCB tracks coated in the stuff is a frightening thought to me.Hard wiring is best to avoid this solder covered track buisness.

Not to worry. Most all circuit boards today use the SMOBC process, which stands for Solder Mask Over Bare Copper. They only tin or solder plate the pads that are used for soldering the components to the board.

The reason this isn't obvious is because most circuit boards use colored solder masks. If you ever get a chance to see a board made using a clear solder mask, you'll see that all the tracks are pristine, pink copper.

se

[Ali Tait]

Yup, and how often do you think high quality ones of the requisite standard you're talking about are used inside in any way affordable commercially produced valve amps?

There's no way that sort of cost could be factored into the budget and for the retail price to remain affordable. Genuinely hi-end commercial designs (say at least over £5k) might be a different matter.

Therefore, what's generally used in mass-market valve equipment is anything but high quality PCBs, with the resulting inevitable sonic penalties. This is precisely why Glenn Croft does what he does!!

Progress? No chance. It's yet another valid example of convenience over quality in today's equipment designs. I'll cite plenty more later!

Marco.

Agreed,but as I said,I was talking from a DIY point of view.

[Marco]

I know that, mate, but remember most people don't inhabit the world of DIY, and thus enjoy its benefits - they have to live with commercial reality....

Marco.

[Ali Tait]

Hi Ali,

I completely agree on that point, as it's also my experience with music, on vinyl and CD.

On another point, as a DIY-er, and fellow valve enthusiast, could you do me a favour and extol the virtues of point-to-point wiring in valve designs when done correctly for the benefit of Cemal?

You'll be able to explain the advantages over PCBs in valve equipment better than I can

Right, off for a kip now!

Marco.

LOL,aye,but that's what you asked me to do!

[Reid Malenfant]

You'll be able to explain the advantages over PCBs in valve equipment better than I can

I really think this hard wiring thing is much more to do with the potentially lethal voltages that are found inside valve amplifiers. On top of that you also have devices that run stinking hot with no effective way of cooling them

The result of the above is charred areas of PCB or fairly decent thicknesses of wire that can conduct some of that heat away & that have much thicker insulation compared to solder resist.

I ask you, which would be safer?

I don't think it's much to do with sound quality though much more exotic wiring can be used than a PCB track admittedly. It's down to longevity & safety imo.

Perhaps someone missed this along the line PCBs unless they are drilled to alow cooling will restrict air flow under the chassis. Wires will not restrict airflow to such an extent. Leaking electrolytic capacitors cause PCBs to become conductive, with the voltages present in valve amps this could easily cause a fire with the PCB going up in flames.

Take it from me i have seen what high voltages & leaking capacitors do & it's no laughing matter

Do i need to add anything else or have i said enough?

[Marco]

Hi Mark,

Yes I saw that, and indeed referred to it in one of my posts... I agree, but aside from that, there are also clear sonic advantages with hard-wiring, as opposed to using (cheap) PCBs - I've heard them!

Marco.