The Truth Pre Amp Review

[ZööZ]

Jds atom has two inputs and more voltage available along with massively superior measurments for a tenth of this price

Stating the obvious but you get an excellent hp amp also

 

[Limopard]

Hallucinations aren't side effects of a covid vaccine as far as I know. So this "product" is real and they charge real money for it?

 

[Veri]

Engineering and safety underwriting by Etsy. Curious as to what the motivation was to get it tested or whether the member who sent it in has some sort of a tie to the builder? I won't dare use the term manufacturer for this box.

I imagine this product once had or has some popularity on certain forums. That's how these things go..

 

[AudioSceptic]

I’m feeling a little shameful here, I’m sure I should know this. What does the etc. represent? I can‘t think of what else the distribution of sound relates to.

Pace? Timing?

 

[sacguy231]

Wow, build looks incredibly shoddy. Like something that came from a middle school science fair. Ugh.

 

[solderdude]

@amirm This isn't even half bad performance for a couple of LDR's in the signal path but most likely with the volume all the way up.
This is where it performs best.

The coffee LDR (which I suppose he never sent to you) may perform somewhat better.

What's interesting to measure:

Input resistance (Ohms with a simple meter) variance over the total volume control range but that may just be another opamp in 'follower' mode with a > 1Mohm input R explaining the high noise floor.
Output resistance over the volume control range. It may have a buffer in it's output path (opamp ?) so DC offset on the output may be a thing.

Distortion measurement with the volume control at -6dB and -20dB for instance.

Distortion with say... 4V in.

 

[Loathecliff]

View attachment 132697

The pic reveals an elechronic obscenity.

 

[rodrigaj]

For those wondering "why" and "how", "The Truth" goes back to Arthur Salvatore review:
http://www.high-endaudio.com/RC-Linestages.html
from this website:
http://www.high-endaudio.com/philos.html

I believe that is where the audiophile reverence for this product began.

 

[Sonny1]

Amir can’t handle the Truth…preamp. This pre is stranger than fiction!

Would love to see a review of the Dude preamp. Remember that was the flavor of the week a few years back. A favorite of the perpetually hysterical internet “influencers”. Guys who seemed to discover breakthrough (and expensive) game changing products on a daily basis and shout about them to the internet world. Audiocircle was infested with those guys, hopping in those Wild West days before becoming the ghost town it is today. Exciting times. I wasted a lot of time abs money chasing the audio holy grail.

 

[B4ICU]

View attachment 132697

I guess the name is like a Wizard of Oz reference or something.

This may explain some of the test results. Especially the bad cross talk. Look at the right side, the green wires between the inputs and the white selector, are not shielded and placed in close proximity in parallel. Definitely not a good practice of design. I would suspect that the idea is of
someone who's understanding in basic Analog design simply does not exist. A disaster is written all over it.

In overall, I see two power supplies (eBay?) that are hard wired to the AC. The "GND plate" is the bare wire connected between the two. 4 GND
green wires are going to 3 PCB's kind of VERY LOW TECH home made. On the middle PCB there is a TO220 (black case with 3 legs), most likely a
DC regulator, that is soldered very poorly. No QA of a major firm would approve this or any of the catastrophic design.
This can explain well, why it's better to have a top caver.

I would like this design better:

The inputs are connected to a PCB directly. The input selector is on the same board, and the knob is using a long metal bar to do the journey inside: No wires. No cross talk.
I'm not a big fun of tubes, and I like more designs that a separation wall is placed between the Amp and PS, This is an analog PS. The "Truth Pre Amp " Ps is a switching PS!
As for the name, what is the truth in this pre-Amp., to deserve such a neam?
I think that the name: "deception" or lie would fit the product better.

 

[Ron Texas]

Preamps are a vanishing category. Many high end systems are all digital with a dac hooked directly to a power amp. Alternatively, a good AV receiver or controller is used.

 

[AudioSceptic]

For those wondering "why" and "how", "The Truth" goes back to Arthur Salvatore review:
http://www.high-endaudio.com/RC-Linestages.html
from this website:
http://www.high-endaudio.com/philos.html

I believe that is where the audiophile reverence for this product began.

I know I should've resisted going there, but this is beyond belief

I believe "The Truth" line stage is the most important audio component available today. It does not have universal applicability and it also has some impractical features but, within its general component class, it stands by itself, sui generis and "one of a kind". More than that, "The Truth" line stage can even be thought of as a "tool" and/or Reference for both audio designers and those serious audiophiles interested in finally learning the true (no pun intended) capabilities, and limitations, of both their sources and their current line stages.

 

[Laserjock]

I was wondering about the photocell comment thinking that was a mistake.
Further reading and seeing the description made me understand the concept but it definitely looks like a one and done project for seeing if something like this would work.

This isn’t a design used anywhere else in the audio world, is it?

 

[Cahudson42]

Truth meet Ciunas.

 

[bboris77]

The designer's name is Ed Schilling. You cannot write this stuff.

Maybe this is where Jason got his idea for the spelling of his company's name.

P.S. I am usually not a mean person, and I do have a lot of affinity for a small company that tries to innovate in this field. What triggered me here is the obvious attempt to shill a product that is average in its performance (and potentially unsafe) to a naive audiophile that happens to be loaded.

 

[Francis Vaughan]

This isn’t a design used anywhere else in the audio world, is it?

Cadmium Sulphide light dependant resistors as volume controls has been around forever. Like I wrote earlier it is an idea that never seems to want to die despite the very significant problems with noise and non-linear response and non-linearities in resistance.
Elsewhere they get called a Vactrol. If you look into the world of tube guitar amplifiers you see vactrols used a lot to switch stuff, in old peak limiters and synthesisers. Anywhere where a remote controlled resistance is needed that has a passably fast response or there is a need for isolation.
So in audio vactrol peak limiters will have been used a lot in earlier recordings. Recording engineers quickly learned the particular distortion sound they gave and used it as yet another artistic tool to shape the sound. Pretty much as they used every limiter.

 

[dfuller]

We need a panther for products that are simply dangerous.

A "caution" panther, perhaps.

@Francis Vaughan , cadmium in LDRs is part of why they've largely been phased out - they don't meet RoHS standards. Well, that and the massive inconsistency component-to-component. I seem to recall reading/watching an interview with Mike Soldano where he said part of the reason the new revision of the SLO got rid of the LDRs in favor of relays was because half of what he bought straight up didn't meet spec.

 

[Francis Vaughan]

I seem to recall reading/watching an interview with Mike Soldano where he said part of the reason the new revision of the SLO got rid of the LDRs in favor of relays was because half of what he bought straight up didn't meet spec.

Doesn't surprise me in the least. For a big name model like the SLO you need reliability and consistency. Vactrols are, in the modern world, a device that has no reason to exist. Tube guitar amps however so value the vintage mojo that is gets little short of clinically obsessive.

 

[Laserjock]

Cadmium Sulphide light dependant resistors as volume controls has been around forever. Like I wrote earlier it is an idea that never seems to want to die despite the very significant problems with noise and non-linear response and non-linearities in resistance.
Elsewhere they get called a Vactrol. If you look into the world of tube guitar amplifiers you see vactrols used a lot to switch stuff, in old peak limiters and synthesisers. Anywhere where a remote controlled resistance is needed that has a passably fast response or there is a need for isolation.
So in audio vactrol peak limiters will have been used a lot in earlier recordings. Recording engineers quickly learned the particular distortion sound they gave and used it as yet another artistic tool to shape the sound. Pretty much as they used every limiter.

Thanks for this. Makes a little more sense now but reminds me of the resurgence of “vinyl” without the nostalgia..

Adding Cadmium to the mix makes it an even more compromising design choice.

 

[aasearles]

Well, it's now obvious we're in a post-truth era!