For sure.
Yet, in the 70th, we were aware of the 'grainy' sound that issued from a carbon pot (and carbon agglomerated resistances), and replaced them by a gold plated 24 pos switch and resistances bridge. An other advantage is that you can make-it constant impedance.
45 years later, i can testify that it still work like the first day.
This said, this is true for signal only. It would be stupid to change adjustable resistances where they just set a DC that can be shunted by a cap.
Attachments
Last edited:
I use these 40 step resistive attenuators. They're quite nice and have a feel as good or better than the Seiden switches. They've eliminated the wiper contact by using a highly flexible wire.
se
An externally hosted image should be here but it was not working when we last tested it.
se
In the Blowtorch case the resistance is needed. It can't be shunted by a cap for desired results of broadband gain adjustment.
The Blowtorch used TKD switched attenuators. Pretty good, but they can get noisy. Better than Alps, comparable to P&G linear faders.
In case of potentiometers, I now feel that Frank is right all the way, and then some. I used to think most were about the same, until I changed one cheap pot (volume) on my H7K 6550 integrated amp, and stuck in an Alps blue pot. For months afterwards, I had trouble believeing what I was hearing, it went from a 2D perspective to a full 3D perspective. Lots of space, "air" the design obviously had in it, but was subsequently killed off by a cheap and nasty volum pot. In general, much as I like H/K roducts, my standard issue with them are poor quality pots and trim pots.
In fact, H/K will also use Alps Blue pots for volume control on their top of their line model of the day (1990-1999), the HK 680 integrated amp. To me, Alps Blue is the default pot, it's either that or something better. Pots can kill a lot of possible good sound.
In fact, H/K will also use Alps Blue pots for volume control on their top of their line model of the day (1990-1999), the HK 680 integrated amp. To me, Alps Blue is the default pot, it's either that or something better. Pots can kill a lot of possible good sound.
I have not experienced that with replacing an Re as a high quality multi-turn trimmer. If I did, I wouldnt use it.
THx-RNMarsh
Last edited:
For a trial period about 6 months during a particularly minimalist fad I tried without an attenuator at all, simply arranging the gain structure to suit a carefully chosen level which conveyed realism for most recordings. It's an interesting experiment, easy to simulate just leave the attenuator alone having found an optimal position that floats the boat. For critical listening it's fine I found. I still try to listen at a consistent level, the effect level has on psychoacoustics is profound.
I would only use silver contacts if the switch was hermetically sealed. Even then, I would move/wipe the contacts now and then to break any possible oxide build-up. Gold over silver works better.
Many of the highest performance products -- test equipment - use small signal sealed relays..... small hermetically sealed --- used in Audio Precision, ShibaSoku and Several other High-End distortion analyzers and ultra low distortion generators. Might be used in audio. Never tried them though. Hard to source.
THx-RNMarsh
Last edited:
Sounds good ... I'm doing some experiments on a plain laptop's internal sound, and I'm always running at 100% volume - so even digital attenuation is taken out of the mix. Subjective results are surprisingly good - and one can see why at least in the processor behaviour; the player software is running almost constantly at 0% CPU time, it's doing no extra fiddling, just dumping the data into the DAC area.
Thanks for the reminder, John. Yes, I used matched high Idss pFETs (J271), since there's no source resistors.
I think that when servicing a piece of expensive equipment, it is extremely important to absolutely understand everything you can about it.
Serious reply # 1:
Ed, I see where you come from, but please consider. The reasoning that jitter performance is determined by the final DAC fits perfectly with all what we know about these things and processes, and also fits perfectly with what we can measure on this.
The only opposition comes from casual, uncontrolled, unspecified and undocumented 'listening tests'.
Now you propose that I do one more listening test. If that is also casual, uncontrolled, unspecified and undocumented, it has no value whatsoever and I am wasting my time.
If however you suggest I do a fully documented, controlled and double blind listening test, I will be willing to send you my rate sheet with pleasure. But to be honest, I'd rather you hired someone else for this.
So, again Ed, no offense meant, but one should really think these things through before throwing out casual suggestions that potentially have big implications.
Jan
Less serious reply # 2 (the kind most often given):
Ed, I can see where you come from. You should be pleased that I did the listening test you suggested and I can confirm that the final DAC does indeed determine the audible performance.
Jan
The plating on the copper traces or in the via barrel is porous.
So an 18um thick copper trace on the outer layer of a multi-layer PCB that is plated up to 35um has a higher resistance than a 35um copper foil that might be used for the internal layers.
This is particularly important in high speed digital designs where striplines (which are based on copper foils in the internal layers of a PCB stackup) are preferred to microstrips (which use the outer layers in a PCB stackup). The stripline has more predictable and consistent performance compared to the microstrip.
Is there anybody here who still uses 35um copper, hasn't everybody gone over to 70 um, or at least 50 um? Copper plating, that is.
Fix the jitter and you fix a lot of sonic problems.
Sort of a two street....jitter will excite wrong downstream behaviours.... and fixing wrong downstream behaviours makes jitter less objectionable.
Jitter still needs to be fixed though.
Dan.
Wanna lay bets on how long it lasts ?.
I expect from past behaviours, that after the Vendetta is working and Bybee is mentioned it will all change from one minute to the next.
So it goes when sycophant/psychopaths go to work.
Dan.
Oh, NOOOOOOOO ! Not that name ! Don't open the Pandora's box !!!!
The forces of evil will spread on earth at a speed superior to that of light while the laws of physics will suffer the ultimate outrages !
An army of bloodthirsty objectivists will rush on the poor ordinary people we are ...
I doubt we could survive to such a crisis !
Last edited:
- Status
- Not open for further replies.