Considering the low level signals they are playing with, they have spread everything out rather a lot! it always puzzles me why go to all the effort of adding boutique components then spread everything out, exposing the low level signals to both PCB parasitics and EMI interference due to the large loop areas and monopole structures formed by the excessively long traces...
I am getting a sense of deja vu regarding the cap discussion, I am sure JC has shown his 30+ year old findings before...
Cool, down the block from work. I should do them something better than that $50 pre-amp, exclusive deal, etc. 😀
Sutherland Engineering Phono Block monoblock phono preamplifier Page 2 | Stereophile.com
A nice solid opamp based design.
LME4990 perhaps?
A nice solid opamp based design.
LME4990 perhaps?
SMT only? Also not optimal from MM, even though they all do it. The world needs a 1nV FET op-amp but the die would not fit in an 8 lead SOIC so JC's job is safe.
Coils have mechanical resonances too.
The measurements where taken with an accelerometer.
Sorry, it is in german again :
Strassacker, Komponenten: Lautsprecher, Frequenzweichen, Bauelemente
The measurements where taken with an accelerometer.
Sorry, it is in german again :
Strassacker, Komponenten: Lautsprecher, Frequenzweichen, Bauelemente
Coils have mechanical resonances too.
The measurements where taken with an accelerometer.
Sorry, it is in german again :
Strassacker, Komponenten: Lautsprecher, Frequenzweichen, Bauelemente
The measurements where taken with an accelerometer.
Sorry, it is in german again :
Strassacker, Komponenten: Lautsprecher, Frequenzweichen, Bauelemente
Sutherland offers another 2-case phono affair, with a comparable number of CDE electrolytic caps inside, the Duo model, for $4k retail.
As a block customer, I'd feel somewhat violated by his tapping feet at the bank.
Getting back to caps, I think that vibration sensitivity and long term reliability is where we should look, beyond using the best materials available as well.
Listen to Richard Marsh. He has experience in these matters. I am still puzzled as how I might best test relative vibration sensitivity of different quality caps.
Listen to Richard Marsh. He has experience in these matters. I am still puzzled as how I might best test relative vibration sensitivity of different quality caps.
Put 'em in a circuit at the position you want to use them and tap with a pencil while listening to the output. That doesn't make a great story, but it works.
With mass-produced polypropylene caps (like Wima or Panasonic), you'll see very little to no effect. PTFE are worse. "Hand made" "limited production" can be quite variable.
With mass-produced polypropylene caps (like Wima or Panasonic), you'll see very little to no effect. PTFE are worse. "Hand made" "limited production" can be quite variable.
How to capture the hipster cache? This is related more to the "vinyl revolution" than the latest $100k statement table (IMHO of course). One local alternative record lable sells Regas with the USB dongles as well as their records. It's a hip thing to have a table and some LP's around the pad.
I hear the latest problem is that the hipster's (they used that word) are stealing the custom glassware that the bars are using for their signature fancy cocktails. Someone has to tell me why the wine prices continue to rise while goofy cocktails are the drink of choice for a large part of the single and lots of disposable income crowd. I mean we never stole the Riedels
Last edited:
Its a generation thing, they grow up stealing downloads and intellectual property , whats a few glasses ...
electrolytics should have no air gaps, are fluid (gel) filled, the electrolyte must have intimate contact right up to the Al/AlO2 dielectric
the "not tightly wound" comment doesn't seem to be relevant - the deeply etched Al foil simply can't be tightly wound, is irrelevant to its mechanical response
the trapped air affecting the self-healing/reliability of metallized film caps should also be by itself irrelevant to audio apps - our films shouldn't be subject to repeated overvoltage that industrial motor caps see
but the measures taken to exclude the trapped air for reliability could be good for audio too - if you were so cheap as to use met-film instead of proper foil electrodes for audio
Last edited:
Vibrate the cap in question with a small pezo device touching it in circuit and record the output . Worth a try . Pezo device is controlable and repeatable as to volume and tone . Pencils work for finding microphonic tubes and such.
Last edited:
If full frequency sweep is not required, suspend the piece of PCB material at its corners on rubber rings (make some sort of sub-chassis), solder cap in place to model the real life situation and attach vibrator from the broken mobile phone to the PCB.
The impulse from a pencil tap has a very broad spectrum.
Piezo excitation can cause unintended AC pickup from the excitation signal.
Piezo excitation can cause unintended AC pickup from the excitation signal.
- Status
- Not open for further replies.