kakishibu
Ha! That’s poorly dissolved kakishibu - a persimmon extract that was used in Japan to waterproof and durablize paper (to make something like oil-paper). I just slather it on to protect the electrolytic innards from dehydration...
I have one question for you though... when I attached the yellow-green ES shield wire of my torroid to the VSPS ground it sparked and killed the signal. When I attach it to the third prong (apartment building ground) I get hum. What should I do with it? Is my transformer’s shield shorted internally?
Thanks again,
Aron
Ha! That’s poorly dissolved kakishibu - a persimmon extract that was used in Japan to waterproof and durablize paper (to make something like oil-paper). I just slather it on to protect the electrolytic innards from dehydration...
I have one question for you though... when I attached the yellow-green ES shield wire of my torroid to the VSPS ground it sparked and killed the signal. When I attach it to the third prong (apartment building ground) I get hum. What should I do with it? Is my transformer’s shield shorted internally?
Thanks again,
Aron
The ES shield should be isolated from anything in the transformer, but it can be floating at a high potential before connected to anything, which might explain the spark.
Btw you should never be playing around with transformer wires with the AC power applied. Connect everything, then turn it on.
If you have the VSPS and power supply in a shared metal box, the VSPS GND must connect to the metal chassis, normally the shield would too, and the PS earth too, but sometimes you can get a ground loop so experiment first disconnecting the earth.
You can check the resistance between the screen and the windings (transformer must be disconnected from everything first, naturally). While unlikely it's possible a short has developed - especially if the transformer is old/beat up)
Btw you should never be playing around with transformer wires with the AC power applied. Connect everything, then turn it on.
If you have the VSPS and power supply in a shared metal box, the VSPS GND must connect to the metal chassis, normally the shield would too, and the PS earth too, but sometimes you can get a ground loop so experiment first disconnecting the earth.
You can check the resistance between the screen and the windings (transformer must be disconnected from everything first, naturally). While unlikely it's possible a short has developed - especially if the transformer is old/beat up)
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Stunned ! (heads out to Persimmon trees....nope..spring too early
)Those big (Carbon ?) Resistors...!
and "Mono" ??
Just WOW!
Those glass capacitors, must have been quite expensive. Can you elaborate on those?
I now use styroflex caps from Xicon (bought from Mouser) and was also considering silver Mica (CDE) but they were a bit costly.
Anyway, your glass caps must be something else ...
Really nice job and your excellent carbon composite resistors must really match that Pickering 380 (i also had one with the original heavy tracking red conical stylus).
I think the capacitance for that cartridge must be kept low (100pf or lower) and the impedance high (around 100kΩ).
One thing I remember made a nice improvement is to bypass the decoupling caps at the opamp rails.
I have Fine Gold electrolytics, bypassed with Soviet military PEPT. You could also try a nice oil cap ther too if space allows.
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Hi Evonimous,
The glass caps are amazing, and can be had for $10-15 on eBay, but most are in the pf to very low nf range, and there aren’t that many applications for them in audio circuits. I first became sold on them when I used one as a coupling capacitor. My Brook amp is really unusual in that it has a 1nf cap in the signal path. When I replaced the silver-mica in this position with a glass dialectic cap there was a vast improvement: something now sounded right that hadn’t before, and I was really impressed by how much farther I could now hear into good recordings (what I like to call “downward resolution”).
I picked the VSPS because it is so minimal that it is affordable to build it with the best parts possible - and because I knew that it sounded great even with pedestrian parts. It has gained acclaim despite the intense unconscious bias against the inexpensive audio equipment! The fact that the values of the caps in the critical RIAA circuit were readily available in glass sealed the deal...
RE the Allen Bradley’s: my experience with glass dialectic capacitors and V-cap ODAM’s has convinced me that capacitors are much more limiting in audio circuits. That they commit profound sins of omission, choking the music and sanding-away subtleties. I guess that’s why Dave Slagle and others go to such lengths to build phono preamps without any capacitors at all. Resistors, by contrast, have much less gross effects. In my experience, they exert a more subtle effect on tone and emotional Gestalt.
I replaced the naked bulk foil 47K loading resistors that I initially built my VSPS with with 100K 2W AB’s and the sound became more coherent and organic and tube-like. Not a controlled experiment because the values are different (and 100K is as you note, better for this Pickering), but consistent with previous experiences. Years ago I played with tantalums in a single-ended amp I built and found them hard and closed-in sounding relative to carbon composition resistors. I bet AB’s are responsible for a lot of the best qualities of classic tube gear.
I don’t find carbon comps noisy. Either that, or I find it possible to hear very subtle detail underneath their noise. Less-than-great capacitors, by contrast, though not audibly noisy, really strip away subtle detail.
Finally, to make a good point about the Pickering 380’s need for low capacitance cables. Perhaps Duelund wires aren’t the best in this context. Can you tell me a little more about your experience with a 380? What do you recommend to get the best out of it?
Best,
Dint
Carbon composition resistors are not for everyone.
I use Kamaya and Ohmite which I buy from Mouser.
Would love to try some vintage Allen Bradley at some point.
The truth of the matter is that once you familiarise to the true sound qualities of a carbon comp., it is very hard to go back to metal film types.
In fact, it was RJM (thanks!) that introduced me to them by including them in the BOM (Kamaya 47Ω cc).
I didn't know what to expect due to the sheer volume of bad rep. I had read here and there.
But, once i did some tests and tried them against film-types, I became hooked to their sound..
Carbon films are also OK though. Not that good but their sound falls somewhere between.
What is the stylus you are using?
I used an original 0.7mil conical (red stylus grip) at 4.5 grams VTF.
It tracked very nicely and sounded very special, as you may know...
The total capacitance can be kept below 100pF with the VSPS, provided your interconnects allow for that. When it is possible I just use the thickest solid core copper wire I can. Capacitance is kept really low (around 50pF/m) that way and they sound better than equivalent width stranded copper.
As long as you are below 100pF and around 100-120kΩ impedance, you are following Pickering specs. That is for the Pickering 380 body. Not for the U38 which has different (updated) coils.
In a proper scenario, the 380 will give you a very tube-like sound.
Insane soundtsage width and a very vintage tone.
Relativley rolled-off treble and a very full/impactful low-end.
Mids typically tube-like smooth.
By the way, I also use MUSES01 in my VSPS. I like it. It sound smooth and polite and reminds me a bit of a tube.
But you may also want to try the LM49720HA (metal can version). If bypassed adequately on the rails, it will sound great.
A more clear, lively/dynamic and forward kind of rendition.
I prefer it to the MUSES01 for general purpose.
I use Kamaya and Ohmite which I buy from Mouser.
Would love to try some vintage Allen Bradley at some point.
The truth of the matter is that once you familiarise to the true sound qualities of a carbon comp., it is very hard to go back to metal film types.
In fact, it was RJM (thanks!) that introduced me to them by including them in the BOM (Kamaya 47Ω cc).
I didn't know what to expect due to the sheer volume of bad rep. I had read here and there.
But, once i did some tests and tried them against film-types, I became hooked to their sound..
Carbon films are also OK though. Not that good but their sound falls somewhere between.
What is the stylus you are using?
I used an original 0.7mil conical (red stylus grip) at 4.5 grams VTF.
It tracked very nicely and sounded very special, as you may know...
The total capacitance can be kept below 100pF with the VSPS, provided your interconnects allow for that. When it is possible I just use the thickest solid core copper wire I can. Capacitance is kept really low (around 50pF/m) that way and they sound better than equivalent width stranded copper.
As long as you are below 100pF and around 100-120kΩ impedance, you are following Pickering specs. That is for the Pickering 380 body. Not for the U38 which has different (updated) coils.
In a proper scenario, the 380 will give you a very tube-like sound.
Insane soundtsage width and a very vintage tone.
Relativley rolled-off treble and a very full/impactful low-end.
Mids typically tube-like smooth.
By the way, I also use MUSES01 in my VSPS. I like it. It sound smooth and polite and reminds me a bit of a tube.
But you may also want to try the LM49720HA (metal can version). If bypassed adequately on the rails, it will sound great.
A more clear, lively/dynamic and forward kind of rendition.
I prefer it to the MUSES01 for general purpose.
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Thank you! Interesting convergence, and interesting advice on the phono cable. Do you think 14 gauge Jupiter solid core would suit? Or would you suggest something else? And what about tonearm wire... any suggestions there?
I definitely have the 380 (not the U38) and I think the stylus is elliptical, though I understand that color can be an unreliable guide, and it needs very high tracking force to track properly, so who knows.
It is quite magical, particularly with low-level retrieval - surprising given its monster output. It doesn’t have the air of the one good moving coil I’ve owned (FR202) but cymbals and the like sound delicious and very much like live instruments.
I do have some distortion when things get loud and busy, but it may be my underpowered (10W) amp clipping. My Spendor BC-1’s are only 94db efficient and I hear compression and distortion with loud passages on CD’s as well. I am building a 60 watt Naim-based solid state amp - using a prebuilt Avondale audio amp module - so I am chasing that issue down. These amps have great PRAT and are reportedly a great match for Spendor BC-1’s.
This conversation is inspiring me to, among other things, change all the Avondale’s resistors to AB (along with changing the capacitors to glass/ODAMs. I may also try the LM49720HA, but I will have to start with a new circuit board since I soldered my Muses01 in....
Thanks in advance,
Dint
I definitely have the 380 (not the U38) and I think the stylus is elliptical, though I understand that color can be an unreliable guide, and it needs very high tracking force to track properly, so who knows.
It is quite magical, particularly with low-level retrieval - surprising given its monster output. It doesn’t have the air of the one good moving coil I’ve owned (FR202) but cymbals and the like sound delicious and very much like live instruments.
I do have some distortion when things get loud and busy, but it may be my underpowered (10W) amp clipping. My Spendor BC-1’s are only 94db efficient and I hear compression and distortion with loud passages on CD’s as well. I am building a 60 watt Naim-based solid state amp - using a prebuilt Avondale audio amp module - so I am chasing that issue down. These amps have great PRAT and are reportedly a great match for Spendor BC-1’s.
This conversation is inspiring me to, among other things, change all the Avondale’s resistors to AB (along with changing the capacitors to glass/ODAMs
. I may also try the LM49720HA, but I will have to start with a new circuit board since I soldered my Muses01 in....Thanks in advance,
Dint
Yeah, that Jupiter cable will be great.
Only drawback with solid core copper of such thickness is the stiffness.
Hard to work with it, but will sound nice.
For the tonearm, things are a bit less easy.
Solid core is stiff and that can be problematic.
So the options are limited. Either get some litz wires of 34AWG, or get some 38AWG magnet wire, bundle 3 together and build a 34AWG equivalent.
If tonearm allows for it, you could use 30AWG silver plated single core copper Kynar wire.
Basically, same rules apply, use the thickest you can (single core), plated or not. Pure silver could also be used but have no experience on how it might affect sound.
Distortion is a common issue with this cartridge.
Its insane output (15mV or more) will overload the inputs of everything down its path. Usually the first victim is the phono stage. Fortunately VSPS seems to not care. So as you said, you want to look further down the chain for clipping.
Yeah, If you can, just change to carbon composition the ones that are directly accross the signal path. Capacitors too. Will most definitely change it for the better I guess.
Only drawback with solid core copper of such thickness is the stiffness.
Hard to work with it, but will sound nice.
For the tonearm, things are a bit less easy.
Solid core is stiff and that can be problematic.
So the options are limited. Either get some litz wires of 34AWG, or get some 38AWG magnet wire, bundle 3 together and build a 34AWG equivalent.
If tonearm allows for it, you could use 30AWG silver plated single core copper Kynar wire.
Basically, same rules apply, use the thickest you can (single core), plated or not. Pure silver could also be used but have no experience on how it might affect sound.
Distortion is a common issue with this cartridge.
Its insane output (15mV or more) will overload the inputs of everything down its path. Usually the first victim is the phono stage. Fortunately VSPS seems to not care. So as you said, you want to look further down the chain for clipping.
Yeah, If you can, just change to carbon composition the ones that are directly accross the signal path. Capacitors too. Will most definitely change it for the better I guess.
That's because the VSPS uses an active, single stage equalization topology. The treble (which has the highest voltage signal coming off the record) is attenuated relative to the rest of the signal at the same time all the output is being amplified. This minimizes headroom issues.
That said, you'd want to reduce the gain to match the cartridge output, down to something like 30 dB I would think.
That’s interesting Richard. I think I should go up to 2.2K for R2 but I have a passive pre and gain is a problem with some recordings. The Muses OPAMP has relatively low gain, so that’s a reason to consider a change in OPAMPs, notwithstanding the work involved (I soldered the Muses in). I bought a NOS LM49860 on eBay from a seller in France and when it arrives will probably try that,
Update: In an effort to get rid of a little residual noise/hum that I still have at full volume, I replaced the voltage regulators with discrete models from Sparkos Laboratories.
The effect was surprising. Not only did I lose the hum and noise, but the sound became more lucid: congested passages cleared up, and everything started sounding more cohesive and musical. There was also a subtle change that away from darkness and toward illumination, if that makes any sense. Starting to sound pretty magical. Highly recommended.
Dint
Update: In an effort to get rid of a little residual noise/hum that I still have at full volume, I replaced the voltage regulators with discrete models from Sparkos Laboratories.
The effect was surprising. Not only did I lose the hum and noise, but the sound became more lucid: congested passages cleared up, and everything started sounding more cohesive and musical. There was also a subtle change that away from darkness and toward illumination, if that makes any sense. Starting to sound pretty magical. Highly recommended.
Dint
Attachments
This is a mod I can get behind. For a time there were dual mono VSPS boards with discrete regulators, but this has been folded into the Emerald since the Emerald supports MM and MC cartridges.
So while I recommend the Emerald as the logical upgrade to the VSPS (dual mono design, MC cartridge support, discrete S-Reg shunt-source regulators, etc), if you want to boost the performance of your existing stereo VSPS replacing the (admittedly poor) LM7x12 regulators would be the obvious step.
/R
Quick question...
I picked up a 47 Labs power supply that was missing it’s ceramic case for next to nothing.
It outputs +/- 19.3 VDC
I wanted to use it as the form factor is good.
I am currently using a Triad 12volt and recommended rectifiers-which I will not use if using 47 Labs power supply.
Should I change anything on the PCB?
Thanks in advance,
Johnny
I picked up a 47 Labs power supply that was missing it’s ceramic case for next to nothing.
It outputs +/- 19.3 VDC
I wanted to use it as the form factor is good.
I am currently using a Triad 12volt and recommended rectifiers-which I will not use if using 47 Labs power supply.
Should I change anything on the PCB?
Thanks in advance,
Johnny
Thanks a lot!
The transformer is a Toyozumi HTW-1203.
The rectifiers are nice though, International Rectifier 8A High Performance Schottky Didoes
The transformer is a Toyozumi HTW-1203.
The rectifiers are nice though, International Rectifier 8A High Performance Schottky Didoes