John Curl's Blowtorch preamplifier part III

Status
Not open for further replies.
Rel Caps were the first WonderCaps. The name was taken by Peter Moncrieff to another manufacturer, years ago. But we mostly stuck to Rel Caps, rather than other companies.
Bill, 8Hz is reasonable (marginally) for a tone arm resonance, and the damper would just lower the Q and therefore increase the pickup of the record warp frequencies.
 
Member
Joined 2014
Paid Member
Well If I HAD to have an 8Hz resonance I'd rather damp it (and consider a record clamp for warps). Every review I have read of high compliance carts on the SME 309/IV/V series has said that the damping is beneficial. The devil of course is that vertical compliance can be much lower than lateral, but of course this is rarely published. Luckily fairly easy to extract once you have a recording off even a blank groove, just needs a split of the signal into M/S rather than L/R. M/S makes a lot of things a lot easier, shame only Decca used it in cartridges.

(And yes for many of you I am discussing advanced Turd Polishing, but it's an enjoyable diversion).
 
“Never attempt to teach an Audiophile* engineering principles; it wastes your time and annoys the Audiophile”

*Substitute any subjectivist audio title here for the same meaning.
Well I am both an audiophile and an engineer so this keeps me on my toes.

I find trying to teach engineers that their textbook theories are not adequate quite arduous at times. At all times. :ill:
 
Rel is alive and well to serious audio manufacturers. Amateurs are encouraged to go elsewhere.

John I gotta laugh, on one side you lambast that designers, especially those of us on this thread who don't use your special sauce parts, and on the other side you tell us to go fly a kite if we want to use those same exact parts you find important. There's no way to win with you!
 
Last edited:
I do not have the dampening option, but will consider one in the future. Or maybe I'll upgrade to the V. 309 has an effective mass of 9.5g, so I'm in the 8Hz region. It works very well actually. Most tonearms currently produced are 12-20g. Everything's geared towards low compliance MCs these days.

Hi!
I have the damping paddle and trough on my SME and I think it was one of the biggest improvements in making the image stable, especially with non-flat LPs. The effect is hard to describe, but I'll try. When the tonearm moves around I think there is a shift in both azimuth and VTA, not to mention the introduction of the LF component which is huge in amplitude relative to the groove signal, but mostly filtered out. The resulting effect on image makes it wander around and flutter a bit proportional to the movement. These audible effects are greatly reduced with that silicone damping fluid and paddle in place. I am using the smallest paddle and it works great! Highly recommended.

Cheers!
Howie
 
Of course, you can easily buy REL Caps through Michael Percy Audio. That is where we sourced most of our Blowtorch parts. I was referring to directly contacting the manufacturer and trying for samples, etc, when you are just an audiophile. The company would rather work with REAL orders, which means real manufacturers. At least that is what I think is appropriate.
 
Disabled Account
Joined 2012
On the sound of capacitors thing, I make the same recommendation as op-amp rolling. Survey the chat boards and try to make any sense of it, you can't but it's still called metadata.

yes, you can. Over time.... wouldn't say at any given second in time you will... but over years. The results have been consistent.


THx-RNMarsh
 
Last edited:
Most speakers on the market today are LR4 with asymmetrical crossovers slopes. Typical lazy engineering, SPL looks flat, it all sounds the same. Right? But what are some time aligned/coherent speakers (non DSP)?

!

what is lazy engineering about applying LR4? It still takes considerable skill to do it right. The better loudspeakers become (and they do!), the more they will all sound alike. They have to, when they converge to transparency. I can tell you now, that all transparent speakers will eventually sound completely identical. Just like many DACs and amplifiers do at the moment already.

BTW, except for some possible offset in acoustic center between drivers, LR4 is both time aligned and coherent. That is one of its charms.
 
Disabled Account
Joined 2012
Of course, you can easily buy REL Caps through Michael Percy Audio. That is where we sourced most of our Blowtorch parts. I was referring to directly contacting the manufacturer and trying for samples, etc, when you are just an audiophile. The company would rather work with REAL orders, which means real manufacturers. At least that is what I think is appropriate.

You can only get samples if you are a manufacturer for real. REL-CAP is a manufacturer to the high reliability requirements of industrial/military under severe and long life conditions. They build to order. No stock. So your order would have to be large enough.

M.Percy orders in large enough quantity so they sell to him at wholesale. If Percy runs out, the lead time can run into weeks or months.


BTW - most if not all audiophile caps are stock parts from someone (usually Asian) who will print your name on it or your logo and put what ever leads etc you like on it. The people marketing them usually have no technical input at all. Just a repackage job. They are not worth paying more for IMO.




THx-RNMarsh
 
Last edited:
Of course, you can easily buy REL Caps through Michael Percy Audio. That is where we sourced most of our Blowtorch parts. I was referring to directly contacting the manufacturer and trying for samples, etc, when you are just an audiophile. The company would rather work with REAL orders, which means real manufacturers. At least that is what I think is appropriate.

Fair enough John. Probably best to say that Rel doesn't take small orders and Michael Percy is a distributor. But we got there. :)
 
This Teflon business is a tough one. IF you can source premium Teflon caps, it is difficult to fault them. However, I would prefer only REL Teflon caps and they are hard to get, AND EXPENSIVE. Especially for production. I just spoke to Bas Lim of Rel Cap about it today. He sampled me Teflon, years ago, but against his better judgement. I now agree with him to stick to quality polystyrene, like RT, or even RTX. They are a little softer on the transients, but they sound smooth and 'right'. It is a bit like we when used to change cams in our cars. A slightly modified cam (sports cam) might not do all that a 3/4 cam would do, but on the street, it is the best choice. Only racers would find 3/4 to full race cams useful. It is the same with the difference between Teflon and Polystyrene, even from the same manufacturer. Also, not just any Teflon cap will sound good for audio, watch out for magnetic leads, etc. The military might approve them, but not audiophile ears.
 
what is lazy engineering about applying LR4? It still takes considerable skill to do it right. The better loudspeakers become (and they do!), the more they will all sound alike. They have to, when they converge to transparency. I can tell you now, that all transparent speakers will eventually sound completely identical. Just like many DACs and amplifiers do at the moment already.

BTW, except for some possible offset in acoustic center between drivers, LR4 is both time aligned and coherent. That is one of its charms.

Yes. Everything sounds the same. We can all go do something else now. It's all been done.

LR4 is the laziest of all, those acoustic slopes practically form themselves, with just one or two parts in the crossover with modern drivers. You have to use asymmetrical slopes for a flat baffle. There's virtually nothing time aligned or coherent about them. But it's something that anyone can do in their sleep so it's everywhere. $20 Dayton mic, free modeling software, and you're good to go!
 
Status
Not open for further replies.