The Truth Pre Amp Review

[Bob from Florida]

The attenuator from Luxman will have several advantages for sure.
A: programmable 'taper'. Memory settings. Can do balance as well as volume control. Much better channel matching (appears to have at least 4 'tracks'), longevity, no scratching pots, smoothness of control easier to achieve, remote control is very easy.
Can be used in AVR's with multiple channels as well which is handy as AVRs are not about absolute performance anyway but about convenience and connectivity.

But... there's a lot of electronics in there. Electronics that can fail, produce noise, add distortion, limit bandwidth in other words change the original signal in other ways than just amplitude.

A similar thing can be said about relay volume control. There are mechanical contacts that can fail (relais). There is less electronic components in its path so less distortion/noise. One can do similar things with this as the Luxman one but this one will be bigger in size and make audible clicks when changing the volume (though that could be damped if needed and very quiet (reed) relays could be used. I have seen relays and reed contacts fail more often than I would like.

Then there is the stepper. Nice L-R balance, taper can be determined in the design, lots of mechanical contacts, longevity depends on the contacts, can have multiple decks. Limited amount of steps, needs separate balance control, needs a coupled motor for remote.
No noise (other than the resistor noise) nor distortion (other than those from the resistor material) is added. Cheaper ones may have 'coarse' steps.

Volpots can be total crap. They can have substantial channel imbalance, the semi-log taper may not be changing at the same spot, they may become scratchy the day they were made, longevity may be poor, needs a motor for remote control.
Tactile feel may be crap but then again... these pots will be very cheap, take up very little space (try to use all of the above in your portable amp).
Then again there are also very well made pots that do not cost an arm ad a leg, have good enough tracking over the most used volume range and do not scratch .
I have 3 RK27 pots in use for well over 30 years and all of them still feel 'nice', don't scratch. One can even get these motorized if need be.
It is better than the LDR and the wiper contacts and resistance tracks are not a problem (obviously) in this pot.
They are simple and do not add distortion and noise that is higher than that of the needed electronic components that are used in front and after the volume control.

So.. it depends on what factors are important to you what your top pick would be. Volpots certainly are better than any LDR. LDR's can introduce distortion and noise that may be preferred by some. More accurate (closer to the truth when truth means signal fidelity) LDR's are not.

I appreciate the balanced thoughtful reply. The electronics involved in the Luxman is indeed more complex. The wisdom of this purchase will play out over time - 3.5 years left of the 5 year warranty. So far so good. The Yamaha version - A-S1100 - I bought prior to the Luxman had to be returned within the 30 day window. Within 3 days its computerized attenuator started changing volume on its own..... So, I do have some idea of the complexity risk.

 

[Bob from Florida]

Too much gain cannot be solved by a stepped attenuator since it suffers from too few steps available in the usable range. If you don't want to change components add a fixed attenuator at the appropriate place in the audio chain.

The 24 step attenuator had the lack of steps issue. I solved that with 4 precision .1% resistors as a voltage dividers to make the 24 steps useful. When the 48 step version came out I used a 50K .1% resistor in series with a 50K attenuator to drop 6 db before attenuation. This worked pretty much perfectly with efficient speakers with lots of fine adjustability. I wanted to add remote volume capability which is where the Saga came in. The 64 1 db steps - first step from no volume to minimum more than 1 db - worked great. The 88 steps on the Luxman work even better - I cannot distinguish the resolution from a pot. In my experience 64 steps or more are adequate.

 

[steve f]

I’m going to try to add a hopefully final chapter on the Truth preamp Yes the unit under testis my property. I tried to take a picture of the insides, but I get a message that the file is too large??? This unit is actually assembled pretty well. Solder is shiny, with no globs. The wiring isn’t messy. The circuit boards are placed square. An exception was the mismatched volume and balance knobs.
A couple of points need addressing since some members got a few things wrong. As originally delivered the Truth had only one input. I marked it with a Sharpie so I wouldn’t forget. The unit was sent back to Ed Schilling to add a second input. That accounts for the wrong markings. If I was still using it, I’d do it all over with press type. The toggle on the back is the selector for input 1 or 2. It is not a ground lift.
I submitted the Truth without prejudice, and am grateful to Amir for testing it. Because it’s an unusual piece of gear I had hoped would invite a discussion about why it’s popular in some circles, but doesn’t measure well. That obviously didn’t happen.
I am not using it because it doesn’t play nice with my electronic crossover and Sanders Sound ESLs. Current pres are either a Schiit Freya S, or an old Morrison ELAD, an excellent preamp. So that’s the truth about my Truth.

 

[SIY]

I’m going to try to add a hopefully final chapter on the Truth preamp Yes the unit under testis my property. I tried to take a picture of the insides, but I get a message that the file is too large??? This unit is actually assembled pretty well. Solder is shiny, with no globs. The wiring isn’t messy. The circuit boards are placed square. An exception was the mismatched volume and balance knobs.
A couple of points need addressing since some members got a few things wrong. As originally delivered the Truth had only one input. I marked it with a Sharpie so I wouldn’t forget. The unit was sent back to Ed Schilling to add a second input. That accounts for the wrong markings. If I was still using it, I’d do it all over with press type. The toggle on the back is the selector for input 1 or 2. It is not a ground lift.
I submitted the Truth without prejudice, and am grateful to Amir for testing it. Because it’s an unusual piece of gear I had hoped would invite a discussion about why it’s popular in some circles, but doesn’t measure well. That obviously didn’t happen.
I am not using it because it doesn’t play nice with my electronic crossover and Sanders Sound ESLs. Current pres are either a Schiit Freya S, or an old Morrison ELAD, an excellent preamp. So that’s the truth about my Truth.

I’d love to see Don Morrison’s reaction to this preamp.

 

[amirm]

I’m going to try to add a hopefully final chapter on the Truth preamp Yes the unit under testis my property. I tried to take a picture of the insides, but I get a message that the file is too large???

We have a 1 megabyte limit on uploaded pictures so you need to resize/reduce its size somehow to post. Or else use an external hosting site. Our storage costs are high because our server uses SSD for speed so I am trying to control that.

 

[KSTR]

We have a 1 megabyte limit on uploaded pictures so you need to resize/reduce its size somehow to post. Or else use an external hosting site. Our storage costs are high because our server uses SSD for speed so I am trying to control that.

Is 1MB the limit for other files as well?

 

[MakeMineVinyl]

I I had hoped would invite a discussion about why it’s popular in some circles, but doesn’t measure well. That obviously didn’t happen.

Products which don't 'measure well' but which are popular are very common - as a matter of fact, my room is stuffed with such devices. The reason someone would purchase something such as this are diverse. In my case, being an engineer (and musician), I looked hard at my overall signal chain's needs and made pro/con evaluations of which type of gear I would use (or design myself mostly). At the other end of the spectrum are non technical people who purchase mostly by reading about it in reviews or online, or per a dealer's recommendation. This can be a dicey area as there are both reputable and not-so-reputable vendors and some vendors who simply do not know best design and/or build practices. I think the preamp in question falls into this last category. Its a brutally simple device which could be thrown together by just about anyone with a basic knowledge of electronics, but - and this is important - there is no 'magic' involved in how the end result works. Electronics is a very, very mature and well understood field.

 

[steve f]

I’d love to see Don Morrison’s reaction to this preamp.

Morrison probably would call it a dog’s breakfast. I think he’s a a Canadian national treasure.

 

[SIY]

Morrison probably would call it a dog’s breakfast. I think he’s a a Canadian national treasure.

The story about The Umbrella Effect was one of the great classics in audio.

 

[Mountain Goat]

Never heard of Don Morrison before today, but this one is good:

https://www.morrisonaudio.com/blog/2015/12/10/ye-spotted-snakes

 

[DonH56]

I’m going to try to add a hopefully final chapter on the Truth preamp Yes the unit under testis my property. I tried to take a picture of the insides, but I get a message that the file is too large??? This unit is actually assembled pretty well. Solder is shiny, with no globs. The wiring isn’t messy. The circuit boards are placed square. An exception was the mismatched volume and balance knobs.
A couple of points need addressing since some members got a few things wrong. As originally delivered the Truth had only one input. I marked it with a Sharpie so I wouldn’t forget. The unit was sent back to Ed Schilling to add a second input. That accounts for the wrong markings. If I was still using it, I’d do it all over with press type. The toggle on the back is the selector for input 1 or 2. It is not a ground lift.
I submitted the Truth without prejudice, and am grateful to Amir for testing it. Because it’s an unusual piece of gear I had hoped would invite a discussion about why it’s popular in some circles, but doesn’t measure well. That obviously didn’t happen.
I am not using it because it doesn’t play nice with my electronic crossover and Sanders Sound ESLs. Current pres are either a Schiit Freya S, or an old Morrison ELAD, an excellent preamp. So that’s the truth about my Truth.

I'd rather hear about your Sanders! I first met Roger long ago when he was still in GA (I think). I talked with Angie a few years ago but not Roger in years even though he's only an hour or so away. Was on my short list of speakers before going with Revels instead.

 

[Poultrygeist]

I live near Ed and have marveled at the Truth and his Horns for years. I'm not much of a numbers guy but they sound wonderful to my ears.

I hope he starts building the Horns again.

 

[Poultrygeist]

We have a 1 megabyte limit on uploaded pictures so you need to resize/reduce its size somehow to post. Or else use an external hosting site. Our storage costs are high because our server uses SSD for speed so I am trying to control that.

My pictures post on every audio forum except this one. FWIW pictures are the life blood of any forum.

 

[Katji]

1Mb is large. It all adds up. ...1080x1080 jpg well under 500Kb. Take a look at Instagram, they'll fix your massive >3000x2000 files.

 

[solderdude]

My pictures post on every audio forum except this one. FWIW pictures are the life blood of any forum.

How hard is it to link to pics hosted elsewhere or to make the pics smaller ?

 

[mhardy6647]

How hard is it to link to pics hosted elsewhere or to make the pics smaller ?

It's not (hard), at all.

Anyone living in the Wintel world, e.g., can use "resize" with a coupla clicks.

If I am in a hurry and/or I don't want to create a file, I usually just copy the image, paste into PowerPoint, and resize it "by eye", then copy & paste to the destination (as was done with the two images above). Easy peasy, and a kindness to the (free!) forums some of us inhabit (and to the space and energy consumed by server farms around the world).

PS, Yeah, I know it was a rhetorical question!

 

[mhardy6647]

That said, and not to flog an erstwhile Equus , I am a fan of (good) third-party hosting services. I like, and use, Flikr -- heck, I even pay for "pro" status (i.e., unlimited bandwidth... at least so far).

DSC_0562 (2) by Mark Hardy, on Flickr

Heck^2, even Amazon (Prime) has a photo hosting service one can use with a coupla clicks. They were quite recently giving out $10 Amazon giftcards for folks to use it.

 

[solderdude]

Your piccas are infinitely better looking than the inside of the truth...

 

[Katji]

^^^True.

 

[mhardy6647]

Your piccas are infinitely better looking than the inside of the truth...

Well... I could show you some of my DIY abominations

On topic (sort of) -- active preamps are hard (as I've said before, probably in this very thread). Almost (!) all of them I've ever tried just made things sound a little worse, a little more rounded off. Impedance matching (buffering) and enhanced "drive" (e.g., for certain deliberately "retro" vacuum tube amplifier designs) are undeniable advantages "on paper" to an active preamp... but I keep goin' back to a passive front end.

This one is (was) DIY, with an early/cheap-ish TVC from Dave Slagle -- but I didn't DIY it, which is why it's not hideous looking (only a little stark).


DSC_4219 (2) by Mark Hardy, on Flickr
Built by AK/Hifihaven forum member "Redboy".
Left is source selector (3 inputs), right is stereo volume control.