Is there a better bargain than the $56 Nobsound Passive Preamp?

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charmerci

Stepped attenuators (resistor ladders) are FAR more precise than any type of smooth pot, including Alps. You don't get "infinite" volume settings with stepped attenuators, but that's actually part of the problem with smooth pots especially when used in their lower range. Channel to channel separation and level matching is near impossible up to a certain threshold. It's like a faucet with a single knob. Try to make the water trickle at a consistent warm temperature and rate ; Really can't be done. But open the valve up a bit to allow water to flow more freely and voila!, consistent temperature and rate. So, if you have ideal gain in your setup, a variable pot can work great...if you can "open up" the pot beyond the threshold where channel separation and volume balance can be trouble.

Stepped resistors provide fixed resistance at each setting for both channels separately. This is much more controlled and precise (especially when high quality resistors are used). This is where these types of pots can get pricey. But, you don't have to deal with quite the variables that smooth pots have.
Well, OK - I won't get the OL Switcher then!

fredgarvin

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Well, OK - I won't get the OL Switcher then!
I have no audible imbalance with mine, at any level. It simply sounds better than my preamp (with the stepped attenuator).  :wink:

charmerci

I have no audible imbalance with mine, at any level. It simply sounds better than my preamp (with the stepped attenuator).  ;)
Well, won't a passive with a stepped pot be better still?

opnly bafld

Well, won't a passive with a stepped pot be better still?

2 OL Switchers, if 1 seems to have any problems.

JohnR

Well, won't a passive with a stepped pot be better still?

Not necessarily. Control range is limited, depending on the gain structure of your system you might not have much range left at all. Also, the switches tend to get clicky, I've had a couple do that (one was a DACT).

OzarkTom

Not necessarily. Control range is limited, depending on the gain structure of your system you might not have much range left at all. Also, the switches tend to get clicky, I've had a couple do that (one was a DACT).

Just when I was going to go on the Dact bandwagon. So how was the sound in comparison to others?

Folsom

Mine have yet to get clickly or anything like that.

Yes the range is limited so choose your settings wisely. That one I posted that's like $200 has settings.

But I'll take a slightly more limited range of superb fidelity to crap fidelity with more range.

Russell Dawkins

I've been happy with my Adcom GFP 750 for many years, partly because it has a switchable active/passive switch. I always run on passive, but it is interesting to be able to switch back and forth to sample quickly the degradation the active mode incurs.

Now I am intrigued by the gains possible with LDR type of preamp, so I googled it and came up with this kit device from Australia:
https://stereocoffee.wixsite.com/ldrpreamp/the-ldr-kit-details
I am impressed with the designer Chris Daly's apparent honesty, and the price seems reasonable at $240 Australian or $169 USD.

Is this old news?

OzarkTom

I've been happy with my Adcom GFP 750 for many years, partly because it has a switchable active/passive switch. I always run on passive, but it is interesting to be able to switch back and forth to sample quickly the degradation the active mode incurs.

Now I am intrigued by the gains possible with LDR type of preamp, so I googled it and came up with this kit device from Australia:
https://stereocoffee.wixsite.com/ldrpreamp/the-ldr-kit-details
I am impressed with the designer Chris Daly's apparent honesty, and the price seems reasonable at $240 Australian or $169 USD.

Is this old news?

The Warp Speed is a LDR passive. Rex likes his Nobsound over the Warp Speed. Just too many passives out there to hear them all.

Folsom

Maybe it curbs a little fatigue for him by smearing slightly?

OzarkTom

Maybe it curbs a little fatigue for him by smearing slightly?

What is the beef now Folsom? Rex now owns a much better sounding amp than yours. Is anyone trashing your amp thread? I am going to buy a Dact passive, and I have sent Rex the info to read. I am sure he will also buy one. He likes to do DIY, he will probably build one. He just sold some audio gear, so he will get his before I do.

Folsom

I am not trying to trash anything. There is nothing unusual about people choosing gear that offsets some attribute. People buy phase destroying stuff all day long for tens to hundreds of thousands, because they like it.

You also have no idea what I have at home. And I couldn’t care less what you think about an amp you’ve probably never heard. For what it costs to build it is overly competitive - there are hundreds of them out there.

fredgarvin

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Well, won't a passive with a stepped pot be better still?

Maybe.

maty

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LDR?

https://www.neurochrome.com/tortuga-audio-ldr3/

Quote
Conclusion

I considered not publishing these results as I generally avoid speaking negatively about my competitors. However, I have received quite a few questions about LDR based volume controls and rather than having to repeat myself, I would rather point people to this page so they can draw their own conclusions from the data.

I approached the measurements of the Tortuga Audio LDR3 with an open mind. I did my absolute best to make the LDR3 shine and I was more than willing to have my skepticism of LDR based volume controls proven wrong. Fortunately measurements tell the truth and the measurements of the LDR3 are not impressive.

OzarkTom

I am not trying to trash anything. There is nothing unusual about people choosing gear that offsets some attribute. People buy phase destroying stuff all day long for tens to hundreds of thousands, because they like it.

You also have no idea what I have at home. And I couldn’t care less what you think about an amp you’ve probably never heard. For what it costs to build it is overly competitive - there are hundreds of them out there.

And you have never heard these new amps that Rex and I now own. There are also others here that owns better amps. But I am sure you believe yours are the best like all amp designers do.

You said you would send me one of your amps to try long time ago, but never did.

Back to the original thread of Nobound and the value it is.

maty

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Btw, something that very few comment in the net is that if we vary the gain the sound profile also changes.

The problem with the cheap chinese DACT (*), like many others, is the only 21 steps. Amps with low watts is OK.

(*) which for years it is spoken very well in the diyaudio forums first and later for its implementation in the Tisbury.

[Big IMG, inside] http://wallofsound.ca/wp-content/uploads/2015/11/tis1.png

maty

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More btw, neither is it much commented that the usual aluminum boxes used in DAC and preamp are usually thin-walled, which is a mistake. Off course, wood is worse.

Low/very low signals are more sensitive to RF/EMI atmospheric.

Better a case with 1 mm steel or 4mm or more aluminum.


Folsom

And you have never heard these new amps that Rex and I now own. There are also others here that owns better amps. But I am sure you believe yours are the best like all amp designers do.

You said you would send me one of your amps to try long time ago, but never did.

Back to the original thread of Nobound and the value it is.

I have no idea what amps you are using. And while I think my 7297 amp is great, it’s just a very well done chipamp (a unique chip). It’s still relatively small potatoes compared to our discrete stuff that costs a fortune, and still behind the next DIY amps. All of it is up for subjective review that will vary. The only thing weird here is that you decided to get personal. I had wanted to send you the demo but it just didn’t work out that way, and then it evolved some past being able to ship.

OzarkTom

I have no idea what amps you are using. And while I think my 7297 amp is great, it’s just a very well done chipamp (a unique chip). It’s still relatively small potatoes compared to our discrete stuff that costs a fortune, and still behind the next DIY amps. All of it is up for subjective review that will vary. The only thing weird here is that you decided to get personal. I had wanted to send you the demo but it just didn’t work out that way, and then it evolved some past being able to ship.
 

I and maybe others got very tired of all the BS of Ncore fanboys several years ago. They said all other amps was trash or junk. Just because you know what is best, let others here slowly learn what is better. It is called trading up. Many are very skeptic that passives can beat their multi thousand dollar tube preamps. The Nobsound and other cheap pasives can be a learning curve for others here. In my sysytem and others here, the Nobsound is not harsh or trashy sounding. Maybe your amp makes then nobsound sound harsh? Or maybe we have all gone deaf?

Because of the Nobsound, I sold my tube preamp for $1275, I can probably now sell my power cord for $50. That makes the Nobsound as extra good value, like this thread is called. Do any Dact sellers  give a 30 day money back guarantee? If so, who? There is an original Danish Dact on Ebay for around $700. Not everyone in the world does DIY.

As one person asked, how much would you charge to make these? People are still spending $3-5K+ for preamps that is inferior to the passives.