• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

Passive Balanced Monitor/Amp controller/preamp

SpaceMonkey

Active Member
Joined
Jan 11, 2020
Messages
226
Likes
218
Hi everyone,
what would you suggest as a simple passive balanced controller/preamp? I would like to get something between DAC XLR outs (with missing volume control) and power amp with XLR inputs. Channel balance is very important to me at all volumes.
Any consensus as to what is a good one?
 
I covered this exact subject yesterday here at ASR - stepped attenuators typically yield the best channel balance. You might want to check out the passive preamps from Khozmo, Axiom or Goldpoint (Picture below) and look at reviews of them. The cheaper Nobsound seems to be a good unit, but uses a continuous attenuator, not a stepped one.

LINK to my post...

Goldpoint SA1X.jpg
 
I covered this exact subject yesterday here at ASR - stepped attenuators typically yield the best channel balance. You might want to check out the passive preamps from Khozmo, Axiom or Goldpoint (Picture below) and look at reviews of them. The cheaper Nobsound seems to be a good unit, but uses a continuous attenuator, not a stepped one.

LINK to my post...

View attachment 52958
Thanks, I was sure I probably missed a thread on the subject.
 
The Schitt Freya S, a selectable passive/active preamp reviewed here at ASR by Amir last month is an excellent unit, but even for a stepped (relay controlled) attenuator, channel balance was good in passive mode, but a bit off in active mode. LINK
 
Thanks, I was sure I probably missed a thread on the subject.

I like the ASR forum website a lot, but I find the search feature a bit primitive.
 
Zeos liked it - but said it had annoying quirks. I would really like to see @amirm test this one. I couldn't find any other reviews other than retail customers.

4.0 out of 5 stars I am ZeosPantera and I approve this Message
Reviewed in the United States on September 25, 2019
Verified Purchase
So I wanted to know what the fuss was all about. And this unit is indeed one of the more accurate ways to adjust volume via XLR or RCA. Converts RCA to XLR and vice versa without switches (not sure how?). Built really well. A tad over-priced but the only one on the market. However, it does need to have a star taken off for several reasons.

1- Poor indication on the knob. I like to know where my volume is set and the divot is not enough.

2-Takes a while to turn on. I'd say 8 second from the off position.It actually varies quite a bit from instant to forever and if you are using the device for the first time you might jam the volume up high when you think it isn't working and it hasn't turned on yet.

3-Occationally gets stuck/jiggles into a freakout zone where you hear it bouncing between what sounds like 2000 relays 80 times a second. This can happen because of placement or due to vibration turning the knob just slightly.

4-The noise.. This thing is noisy. I am tempted to open it up and poly-fil it to silence that clicking. I appreciate it but it is down right distracting when you go to adjust the volume on a quiet song only to realize you have a box of angry cicadas and rattle snakes in front of you.

Overall it's a recommendation just know it isn't perfect. I will continue to use it on important reviews and equipment as I think its doing its job. Just with a few minor annoyances.
 
I also looked at studio contreollers such as Mackie Big Knob Passive. I don't know if anyone had any experience with these and whether they are truly balanced.
 
I also looked at studio contreollers such as Mackie Big Knob Passive. I don't know if anyone had any experience with these and whether they are truly balanced.

Ditto. The Behringer Monitor 1 looks good too, and there are others. There is also the Nobsound passive preamp that was raved about on audiocircle but can reportedly suffer a little channel imbalance at low volume.

https://www.amazon.co.uk/gp/product/B07DJ73KX8/ref=ox_sc_saved_title_4?smid=A2M8DEO6BEJ1QF&psc=1

https://www.audiocircle.com/index.php?topic=161437.0
 
Last edited:
Channel imbalances tend to be concentrated at lower volume levels. There are two simple options at address this. First, use the digital volume control in the source, if it has one. Second, add an inline attenuator to force the volume control into a higher and more accurate range.
 
Martin, can you give a your ownership impressions of this unit?

Was just querying about it yesterday, https://www.audiosciencereview.com/...obsound-shit-or-great.8923/page-2#post-343183
I am happy with it in my system. I use it to balance the volume between a pair of solid state monoblocks driving the bottom cabinet of my speakers with the tube monoblocks driving the top cabinet.

I am not smart enough to see how 8 relays are the voltage divider. Guess it is equivilent to an eight bit dac.
So 256 0.5 dB steps.
The inputs and outputs are RCA. Not balanced.
I don’t know how it works but it does. It has single ended RCA and balanced XLR inputs and outputs. I use balanced XLR and it works as advertised.

Martin
 
I don’t know how it works but it does. It has single ended RCA and balanced XLR inputs and outputs. I use balanced XLR and it works as advertised.

Martin

Looks to switch resistors to attenuate. Missed the XLR’s in the inside picture.
How this attenuates a balance input with resolution using eight relays is trick.
Does it step or seem fine adjustment?
Definately is sweet for 100.00.
Have used a dac that had a PGA4311 that attenuated balanced four channel.
 
So it seems that Mackie Big Knob Passive is actually not balanced :(
1590099415699.png
 
I use this relay based one from AliExpress:
index.php


https://www.aliexpress.com/item/32997802910.html?spm=a2g0s.9042311.0.0.37a54c4dPYMiAM

It's cheaper than the stepped attenuators and works well in my system.

Martin
I too would also recommend the Yisheng Relay Attenuator. Do note it does need a power supply to have sound playing and also to switch the volume.
The seller I ordered from is different from Martin though <https://www.aliexpress.com/item/32905140596.html?spm=a2g0s.9042311.0.0.27424c4dRmOq2j>
If you're in Europe, you can also order through Audiophonics.fr https://www.audiophonics.fr/en/prea...sistor-volume-controller-xlr-rca-p-13183.html>
3DDC4724-62B3-4C1C-B418-52403853DA5F.jpeg



Other more expensive options that include a remote control are as follows:

1. Hattor Audio Mini Passive Preamplifier $810 <http://mockingbirddistribution.com/hattor-audio/mini-passive-active-pre/>
1591731611059.png


2. Khozmo Acoustic Passive Preamplifier $400 (+$200 for Remote) <https://khozmo.com/balanced_stereo.html>
1591731514887.png

1591731540824.png


3. Schiit Audio Freya S Passive or Active <https://www.schiit.com/products/freya-s>
1591731583710.png
 
Last edited:
I too would also recommend the Yisheng Relay Attenuator. Do note it does need a power supply to have sound playing and also to switch the volume.
The seller I ordered from is different from Martin though <https://www.aliexpress.com/item/32905140596.html?spm=a2g0s.9042311.0.0.27424c4dRmOq2j>
If you're in Europe, you can also order through Audiophonics.fr https://www.audiophonics.fr/en/prea...sistor-volume-controller-xlr-rca-p-13183.html>
View attachment 68065


Other more expensive options that include a remote control are as follows:

1. Hattor Audio Mini Passive Preamplifier $810 <http://mockingbirddistribution.com/hattor-audio/mini-passive-active-pre/>
View attachment 68070

2. Khozmo Acoustic Passive Preamplifier $400 (+$200 for Remote) <https://khozmo.com/balanced_stereo.html>
View attachment 68067
View attachment 68068

3. Schiit Audio Freya S Passive or Active <https://www.schiit.com/products/freya-s>
View attachment 68069

I looked at Hattor, Khozmo, Goldpoint and a few others. Price is why I chose the Yisheng. :) That and I only needed a volume control I could set and forget.

Martin
 
I found another gem! This one has a remote control
515E36D9-57C5-40AF-A38E-F47A573F2B3F.jpeg

Edit: I just purchased one :D
 
Last edited:
These are the sellers that have it on Aliexpress. The first link allows you to choose 220V/110V. The second one is 230V by default and requires you to put a note if you need 110V
<https://www.aliexpress.com/item/400...earchweb0_0,searchweb201602_,searchweb201603_>
or
<https://www.aliexpress.com/item/400...earchweb0_0,searchweb201602_,searchweb201603_>

This is the seller (SanChun) on Taobao. They have some advanced versions with wide band frequency control.
Edit: <https://shop152173058.world.taobao.com/?spm=2013.1.1000126.2.7dfa349cJhSNY0>

1591755944344.png
 
Last edited:
Back
Top Bottom