John Curl's Blowtorch preamplifier

[SY]

It's Teflon. You can make a cap out of it, but it will be loose, microphonic, and unrepeatable.

Scott's humor.

 

[audio845]

I'm just a amateur designer but I did spend 10 years as a professional musician so I have a pretty good set of ears. I've been listening to different caps for the past 15 or so years and I CAN hear a difference no matter what the naysayers are crying. Having said that I believe that the Teflon caps (both the Vcaps and the TFTs) sound the best. I like the RTs in small values but in larger values I think the PPFXs are the best sounding next to Teflon (the RTX sound slow and rolled off in comparison). I have no idea why this is, but I can certainly hear the difference. I build tube gear which may also make a difference in how the caps sound with the higher voltages involved.

I have heard multiple possible explanations from DA to damping to self resonance. Perhaps it is a combination of all of these or maybe something that hasn't been measured yet - but the difference is easily audible in tube circuits with their inherent simplicity.

Charlie

I'll guess I'll have to try the plumbers tape. '😉'

 

[h_a]

Does that mean I can't make my own caps with plumber's tape?

😀

Come on! The tube guys have their huge transformers ontop of the chassis, so why not huge rolls of plumber's tape on solid state gear?

Capacitance must be a real joke at this density.

Have fun, Hannes

 

[john curl]

Audio845, that is exactly the kind of input that I appreciate. I wish that I got more of it on this thread, because I can learn from it, if only your studied opinion. When I get a 1/2 dozen opinions just like this from people who don't even know each other, then I know we are on the right track.
For example, when I spoke to JAM, a sometime contributor to this thread, he knew the sound quality of the REL RT's instantly and gave me his independent input. I have never met JAM personally, or listened with him, but we share an amazing 'coincidence' in listening opinions on caps.
However, it may depend on the cap value and application as to which cap is best. For example, for loudspeakers, all bets are off with me, because I have so little experience with making passive speaker crossovers.

 

[nicoch58]

Can I ask what difference signature have rt-teflon$$ on 100nf riaa (Erno phono)

 

[john curl]

I can't access what the cap difference is with other circuits, but I used to have a T mod for a Vendetta SCP-2 that exchanges Teflon for RT polystyrene. I found the Teflons more 'dynamic' in my own phono stage for EQ.

 

[audio845]

Hi nicoch46,

You'll probably hate this kind of answer but to me the teflons sound more "natural". What does that mean? They are more dynamic but also have what I'll call a more correct harmonic signature. An oboe sounds more like an oboe and a clarinet sounds more like a clarinet. I was (am) a pianist and for me the transients both at the start and the stop of a note are very important and the teflons get this better as well.

Now having said all this the difference is small and unless you are shooting for the absolute best you can do, the PPFX or RT would certainly be fine. Either one is reasonably priced.

Charlie

 

[john curl]

I happen to agree, and I don't even know you, Audio845.
I wish it weren't true.

 

[nicoch58]

nice answer

thanks John /Charlie


is great pity that many people do not realize that there are substantial differences by changing just one strategic component ...
in my small experience change the Rload of cartridge from dale to tantalum (that is the first component of the chain) made the sound more sweet with a lot reverb-space info...just some €

 

[Wavebourn]

It greatly depend on where that component is placed, I would not call it a strategic place, but rather a bottleneck.

 

[john curl]

Nichoch46, I, too, use a tantalum resistor for the input of the Vendetta SCP-2, but I use a variable tantalum pot, available only in Japan, and discontinued. Still, it is pretty darn good. Other resistors that I use there are Resista (old, if possible) and old Holco (non-magnetic).

 

[nicoch58]

bottleneck : is better word 😉
the same change resitor in series on step att. gain 10x effect

OT
I have read that putting the Rload back on the tonearm are better ,any one know why?

 

[nicoch58]

Thanks JC for Resista suggestion cheaps and good 😉

like nichicom KG that sound fine to me

Emanuele

 

[Johnloudb]

Not to change the subject here, but I'm curious about how some of these old recordings can sound so good. This Rimsky-Korsakov record has the most beautiful sonics (1950's). It's a mono recording and it has been played to death and has substantial surface noise. Still it's just pleasure to listen to. My dad was also listening to some Arturo Toscanini conducting the New York Phil on CD and said he just really loved it. He said he could just really hear how James Chambers (french horn) sounded on though recordings. I guess Toscanini liked dead halls so he could hear everything. My dad played the french horn.

Anyway, I was just wondering why some of these old recordings sound so good sometimes. Maybe it was the tube microphone preamps or something? Recording technique?

An externally hosted image should be here but it was not working when we last tested it.

 

[john curl]

Tubes in both microphones and record electronics.

 

[john curl]

One of the best places to evaluate resistor quality is as a 'load' for a MC cartridge. The other important place is the feedback resistor in a power amp that goes from the output to the feedback point. The results may differ, since the dynamics are so different, but usually they are similar

 

[nicoch58]

John I ask you becouse I cannot find a good answer ,
were is the right place to jont the 0V ? after the shunt ,or fist or second caps ?

 

[john curl]

I can't say from what I see.

 

[nicoch58]

Thanks ,sorry too general question

Emanuele

 

[Joshua_G]

Tubes in both microphones and record electronics.

Can also be the art of recording and mastering.