The Truth Pre Amp Review

[Koeitje]

Lordy, this is quite a mess.
A quick Google turns up a few internals pics here: https://www.superbestaudiofriends.o...ve-volume-control-for-dacs-sources.860/page-9

Forum comes compete with a snide remark about Amir.

Post above has the other pic I found.

The preamp looks like a total amateur build. There is so much wrong with it I would be utterly ashamed to put my name anywhere near something like this product, and as to charging $1k for it, it is just ridiculous.

The switch on the back is a chassis ground lift. Really. And it the switch would never survive a realistic fault current. It might weld itself solid, it might vaporise before a break blew leaving you with a lethal live chassis. Some versions don't have he list switch. It seems they just don't bother to ground the chassis. The mains wiring inside is not to standard either.

The quality of the soldering is beyond poor. It is what I might expect of a 12 year old doing a circuit build for the first time with poor quality tools. The entire internal layout and construction is quite simply terrible and not of merchantable quality. There is clearly no understanding of ground loops and management of ground return, which will be a contributor to the mains pickup and poor noise figure. Not a cable tie in sight, which along with the terrible soldering will lead to poor reliability.

Now to the circuit. It is an op-amp buffer on the input and output coupled by a light dependant resistor lit by a LED controlled by the volume pot. That is it. There is no light shielding for the LDRs so the chassis had better be light tight to avoid interference from external light sources - especially modern LED lights flickering away. This is a funny idea that keeps raising its head from time to time. The volume control on the front doesn't touch the signal, but just runs the LED. But there are all manner of issues with the idea, poor noise being one of them, and unclear distortion effects in the resistor.

This is a product that needs calling out for what it is. No matter what else, its construction leaves it as an unsafe produce that should not be sold.
There needs to be a panther past the headless one. This is deserving of it.

We need a panther for products that are simply dangerous.

 

[JSmith]

Well at least we all know...





JSmith

 

[Francis Vaughan]

This is not the unit measured here. It looks as if it has an input selector on the front panel

It seems each instance is custom made and configured. Single or dual power supply and combination of inputs and outputs and switching. The core remains the same

 

[3125b]

That would be shabby for a DIY project let alone something sold to the masses, especially at over 1000$ wich is just insane.
Do they not have to prove electrical compliance/safety in the US?

 

[Kaiju]

Truth hurts, ouch!

 

[DSJR]

The niche side of the UK audio scene was toying with LCR 'preamps' but I don't think these had a pukka buffer section added.

https://robmid42.wixsite.com/diyaudiokits/stereo-coffee-preamplifier

A very vocal UK based maker who never ever pulled punches called the LDR's out for having cadmium internally. Big row I remember.

 

[raindance]

This deserves a headless panther more than anything you've reviewed yet, @amirm

 

[renevoorburg]

It looks like the left rotary button is placed lower than the other ?!?

 

[Francis Vaughan]

A very vocal UK based maker who never ever pulled punches called the LDR's out for having cadmium internally

That is just idiotic. We cadmium plate steel all the time. That is what the yellow plating is. Anyone want to call out Revel for the Beryllium in their tweeters? Just as stupid.

 

[KxDx]

Seems to be almost consensus that most of these boutique "built in my garage" devices are overpriced underachievers.

I'm having flashbacks of the jkenny DAC.

 

[bboris77]

There’s a lovely subjective review here https://www.tnt-audio.com/ampli/the_truth_e.html that has topless shots. My favourite paragraph from the review:

Spoiler

My first few listening sessions were a bit disorienting. I was not quite able to put words to my impressions. It took me 2 or 3 days of heavy listening time really start to be able to answer the question “What am I hearing?” I have concluded, and I am still comfortable with this conclusion many months later, that the strangeness was due to the lack of noise and distortion. An impression of something missing. With The Truth Pre Amp not only must one ask “What am I hearing?” but equally as important “What am I not hearing?”.

This “review” turned my stomach upside down. It represents everything that is wrong in this industry. It is shocking to see how the author identifies all the shortcomings of this product and then makes apologies and excuses for all of them.

 

[DSJR]

That is just idiotic. We cadmium plate steel all the time. That is what the yellow plating is. Anyone want to call out Revel for the Beryllium in their tweeters? Just as stupid.

What about eventual recycling? Not challenging, just asking.

 

[sergeauckland]

That is just idiotic. We cadmium plate steel all the time. That is what the yellow plating is. Anyone want to call out Revel for the Beryllium in their tweeters? Just as stupid.

This side of the water, cad plating hasn't been allowed for many years, and CDS cells are doubtful. Richard Dunn was sure that they were illegal.
I understand CDS cells also have an unfortunate property that the resistance has a small dependency on the voltage across the cell, so that generates some harmonic distortion in itself. Not enough to be audible, but quite enough for the numbers to look bad on something that should be entirely passive except for a buffer.

S.

 

[Sir Sanders Zingmore]

The niche side of the UK audio scene was toying with LCR 'preamps' but I don't think these had a pukka buffer section added.

https://robmid42.wixsite.com/diyaudiokits/stereo-coffee-preamplifier

A very vocal UK based maker who never ever pulled punches called the LDR's out for having cadmium internally. Big row I remember.

StereoCoffee ( @stereo coffee) is not from the UK, they are a NZ brand

 

[Nango]

There’s a lovely subjective review here https://www.tnt-audio.com/ampli/the_truth_e.html that has topless shots. My favourite paragraph from the review:

Spoiler

My first few listening sessions were a bit disorienting. I was not quite able to put words to my impressions. It took me 2 or 3 days of heavy listening time really start to be able to answer the question “What am I hearing?” I have concluded, and I am still comfortable with this conclusion many months later, that the strangeness was due to the lack of noise and distortion. An impression of something missing. With The Truth Pre Amp not only must one ask “What am I hearing?” but equally as important “What am I not hearing?”.

These comments disqualify this site TNT for me there is no reason to read there any longer. Thanks for posting!!

 

[Nango]

View attachment 132697

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

Looks like garage ware 100% and finished during one weekend!!! 1000$???? A case for the F.B.I.!!!

 

[AudioSceptic]

Lordy, this is quite a mess.
A quick Google turns up a few internals pics here: https://www.superbestaudiofriends.o...ve-volume-control-for-dacs-sources.860/page-9

Forum comes compete with a snide remark about Amir.

Post above has the other pic I found.

The preamp looks like a total amateur build. There is so much wrong with it I would be utterly ashamed to put my name anywhere near something like this product, and as to charging $1k for it, it is just ridiculous.

The switch on the back is a chassis ground lift. Really. And the switch would never survive a realistic fault current. It might weld itself solid, it might vaporise before a breaker blew leaving you with a lethal live chassis. Some versions don't have the lift switch. It seems then they just don't bother to ground the chassis. The mains wiring inside is not to standard either.

The quality of the soldering is beyond poor. It is what I might expect of a 12 year old doing a circuit build for the first time with poor quality tools. The entire internal layout and construction is quite simply terrible and not of merchantable quality. There is clearly no understanding of ground loops and management of ground return, which will be a contributor to the mains pickup and poor noise figure. Not a cable tie in sight, which along with the terrible soldering will lead to poor reliability.

Now to the circuit. It is an op-amp buffer on the input and output coupled by a light dependant resistor lit by a LED controlled by the volume pot. That is it. There is no light shielding for the LDRs so the chassis had better be light tight to avoid interference from external light sources - especially modern LED lights flickering away. This is a funny idea that keeps raising its head from time to time. The volume control on the front doesn't touch the signal, but just runs the LED. But there are all manner of issues with the idea, poor noise being one of them, and unclear distortion effects in the resistor.

This is a product that needs calling out for what it is. No matter what else, its construction leaves it as an unsafe product that should not be sold.
There needs to be a panther past the headless one. This is deserving of it.

Is there anything worse than this for $1k? It does f*** all and does it badly, the build and finish are below DIY standard, and it's not even safe.

 

[respice finem]

I looked at the calendar and no, it isn't April 1st

1k$, for this, really?

 

[AudioSceptic]

We need a panther for products that are simply dangerous.

One with smoke billowing off it?

 

[DHT 845]

IMO this is the most interesting preamp to measure, also known as MBL 6010d clone, but it is not 1:1 copy in fact

Balanced Preamplifier RCA XLR 10x NE5534D 4x NE5532D ALPS Potentiometer with Remote Control - Audiophonics

Original MBL 6010d measurements are superb, price ab. $20.000

MBL 6010 D preamplifier Measurements | Stereophile.com