I completely agree with you!It is perfectly normal for the balanced signals to be debalanced after the input and rebalanced after the volume control, before the amplifier stage. This has been done for tens of years and is the case even with many devices costing several thousand dollars.
Few devices are fully and consistently balanced.
To see that, you just have to pay attention to whether the volume control has 2 or 4 channels. So stereo vs. quad potentiometer, 2-channel or 4-channel chip on the volume control, 6-8 relays or 12-16 relays, etc.
The cheap Cordial cables are not so cheap for nothing.They're expensive! I'm usually going for Cordial cables (on amazon).
I don't get your point. All my Cordial cables have Rean/Neutrik connectors. Are you saying these are bad connectors?The cheap Cordial cables are not so cheap for nothing.
Really cheap China plugs made of cheap materials are used, just hold a magnet to the jack plug. Only Cordial can tell you whether the cables used are really original.
As is the case everywhere, if a product is cheaper in retail than the parts for it are wholesale, then something is wrong.
You can also find original Cordial cables with high-quality branded connectors, but they are no cheaper than the ready-made cables from Sommercable, Mogami (World's Best Cables) or Gotham.
Please post a picture of your plugs (of the cheap cables), then I can tell you that more precisely.I don't get your point. All my Cordial cables have Rean/Neutrik connectors. Are you saying these are bad connectors?
Of course, these devices can still be improved, but they are low cost/low budget devices that we are talking about here. Most devices on the market with such equipment cost x times more, although they are not necessarily better.I completely agree with you!
A balanced signal is not an end in itself and the device can transform it internally into an unbalance and process it in various ways.
The important thing is how it is implemented in a particular device.
A closer analysis circuits of the SMSL SH-9, SMSL SP400, Topping Pre90 and the latest Topping A90 Discrete revealed the same typical primitive differential amplifier circuit used to convert a balanced signal into an unbalanced one.
The circuit does not have any tuning elements to suppress the common-mode component and looks something like this:
View attachment 250134
As a rule, without tuning and using 1% resistors, this circuit will provide suppression of the common-mode component of about 40 dB, but tuning will allow you to significantly improve this value.
Theoretically, the suppression of the common-mode component can be infinite, but if the resistances are balanced within ±1 Ohm, 80 dB or even more can be expected.
View attachment 250137 View attachment 250138 View attachment 250139 View attachment 250140 View attachment 250141
And we would like a better hardware implementation of this scheme for such a cost of these amplifiers.
You can assume that nothing on the relay-based volume control is worn out. The device can be a maximum of 3 years old, not 30 years.Hi all,
I bought a used SP400 and in my opinion it plays too quietly. For comparison, I have Ho200, which plays much louder.
Does the amplifier sound quieter due to wear of the R2R volume control?
What are the symptoms of worn out R2R volume control?
I have HW version 1.0 on display, does that mean it is very old and the volume control may be worn out?
Hi all,
I bought a used SP400 and in my opinion it plays too quietly. For comparison, I have Ho200, which plays much louder.
Does the amplifier sound quieter due to wear of the R2R volume control?
What are the symptoms of worn out R2R volume control?
I have HW version 1.0 on display, does that mean it is very old and the volume control may be worn out?
The source is smsl su-10 connected via xlr. DT-990 pro headphones, modded cable to balanced. I listen at 40 high gain and it's OK for me. What worries me is that Ho200 is much stronger. I think I read somewhere that the R2R regulation gets damaged over time and the symptom is an increasingly quiet sound. I'm not sure if this is the correct thesis.You can assume that nothing on the relay-based volume control is worn out. The device can be a maximum of 3 years old, not 30 years.
What gain level is the device at and what is the source?
How far from max is 40? Likely the HO200 just has a higher gain setting. If you have plenty of room left to max volume on the Sp400 I wouldnt worry.The source is smsl su-10 connected via xlr. DT-990 pro headphones, modded cable to balanced. I listen at 40 high gain and it's OK for me. What worries me is that Ho200 is much stronger. I think I read somewhere that the R2R regulation gets damaged over time and the symptom is an increasingly quiet sound. I'm not sure if this is the correct thesis.
Yes, the ho200 high gain is 23dB and the sp400 is 11.6.. Nothing to worry about if you're not anywhere near max.Max is 99
This volume control has nothing to do with R2R, so maybe that's why you have incorrect information.The source is smsl su-10 connected via xlr. DT-990 pro headphones, modded cable to balanced. I listen at 40 high gain and it's OK for me. What worries me is that Ho200 is much stronger. I think I read somewhere that the R2R regulation gets damaged over time and the symptom is an increasingly quiet sound. I'm not sure if this is the correct thesis.
The source is smsl su-10 connected via xlr. DT-990 pro headphones, modded cable to balanced. I listen at 40 high gain and it's OK for me. What worries me is that Ho200 is much stronger. I think I read somewhere that the R2R regulation gets damaged over time and the symptom is an increasingly quiet sound. I'm not sure if this is the correct thesis.
L50 has no difference between the balanced and SE inputs which means it works as SE-only input. You can compare specs but the SP400 will have more power. The question is if you need more power.
You'll probably never need more power than the L50 puts out.Just powering Sundara's just now so L50 is fine power wise, thinking longer-term if I'm replacing my L50 for it being faulty.
I know the L50 is only balanced in, not out, but it does seem to deliver pretty decent power on SE. I just struggle at times to figure out Amir's review graphs properly and decipher what would deliver more power to planar headphones lol (If I replace my Sundara it might be going up the HiFiMan range as I really like open back planars).
For example I was looking at the SABAJ A20h as a cheaper replacement for the L50 for now with my Sundara's but even although it's balanced it seems to have less power than the L50 SE for a pair of Sundara's!
The L50 is SE only and therefore has the same power on the XLR output. The A20h only has half the power on SE as on XLR.Just powering Sundara's just now so L50 is fine power wise, thinking longer-term if I'm replacing my L50 for it being faulty.
I know the L50 is only balanced in, not out, but it does seem to deliver pretty decent power on SE. I just struggle at times to figure out Amir's review graphs properly and decipher what would deliver more power to planar headphones lol (If I replace my Sundara it might be going up the HiFiMan range as I really like open back planars).
For example I was looking at the SABAJ A20h as a cheaper replacement for the L50 for now with my Sundara's but even although it's balanced it seems to have less power than the L50 SE for a pair of Sundara's!