“Seem” doesn’t result from measurements. I have some favorite music that I listen to frequently. Just one example: Celine and Babs duet “tell him”. They both have beautiful voices and perfect pitch and spot on together. Nice to hear them as not standing on top of each other (still not great, possibly the result of either miking or mastering).
What a cool way to save $8,000!
In the end, us audiophiles use our ears as the final arbiter as to whether a piece of audio gear is worthy of keeping. Enjoy.
Cite?
Absolutely! Just not the only arbiter.
I would agree. It’s just like anything else, the more you practice a certain skill, or use your brain or muscles, the further you develop them.
I believe you can also improve your short-term auditory memory.
In an earlier post I said this about source components connected to my PMG S200:
Here are some mixes that fail sonically. Remember, these are specific to my system:
- Inserting PS Audio BHK Signature Preamp into the chain
- Inserting the Audial S5b into the chain (Audial S5b works superbly with the Naim system)
Today I got schooled by Google AI on input sensitivity. I asked Google why certain source components such as the Audial S5b DAC sounded weaker at the same volume setting than other DACs such as the DirectStream DAC Mk2. But the Audial sounded very loud and powerful when connected to my Naim NAC 122X. Here’s what it said:
The volume difference you are experiencing is caused by a significant mismatch in input sensitivity between the two preamplifiers, not an electrical impedance compatibility issue.
Why the Naim Sounds Much Louder
Your Audial S5b DAC has a very low output impedance (3 ohms or 30 ohms depending on the configuration), which perfectly bridges into the standard input impedances of both preamplifiers (47k ohms on the Naim and 50k–100k ohms on the PS Audio PMG / Stellar Gold). Impedance-wise, both connections are electronically healthy. [1, 2, 3, 4]
The discrepancy comes down to how much incoming voltage each preamplifier requires to reach its full volume:
- The Naim NAC 122X has ultra-high input sensitivity: It requires a tiny input signal of just 75mV (0.075V) to drive it to full rated output. According to Hi-Fi Corner, “Naim pre-amps have a high input sensitivity of 75 mV.” Because the Audial DAC outputs a standard line-level voltage (typically around 2V RMS), it easily floods the Naim’s input stage. This forces you to keep the Naim’s volume knob very low, giving the illusion of immense “power” and loudness early on the dial. [1, 2]
- The PS Audio PMG Preamp uses modern gain-staging: Like the PS Audio StellarGold Preamplifier and high-end BHK Signature lines, the PMG is engineered around standard modern inputs. It expects a full 1V to 2V RMS source signal to utilize its volume sweep smoothly. [1, 2, 3]
Because the PS Audio requires significantly more voltage than the Naim to reach the same volume level, the sound will feel “weak” at the exact same volume position. However, this is actually preferred; it gives you a much finer, less compressed control over your volume sweep without introducing early distortion.
How to Fix It
- Use Input Trim/Gain (If Available): If you are using a modern digital PS Audio preamp variant like the PS Audio Stellar Strata, check the settings menu. Many PS Audio units feature an Input Trim Gain that allows you to boost or cut individual inputs by up to +/-10dB to level-match various sources. [1]
- Switch to Balanced XLR Connections: If you are currently using single-ended RCA cables, switch to balanced XLR. The Audial S5b’s optional transformer-coupled layout or standard balanced paths usually double the signal voltage. Concurrently, the PS Audio PMG Line treats balanced inputs natively, which will instantly grant you an approximate 6dB boost in gain. [1, 2, 3]
- Turn the Volume Up: If no trim options exist and you are already using XLR, simply turn the PS Audio volume dial up higher than you are used to with the Naim. As long as you aren’t hearing distortion or floor hiss, running a modern preamp higher up its gain curve is safe and intended.
Last week I traded the BHK Signature Preamp for the PMG Signature Preamp with great results. After the first three days of listening with the PMG Signature Preamp, I was convinced – and yesterday the BHK Preamp (trade-in) was boxed and shipped to PS Audio.
Nevertheless, I noticed that my Schiit Singular (Byggy) and DirectStream DAC Mk2 sounded equally loud at the same preamp volume level, but the Audial sounded noticeably quieter.
So about an hour ago I used How to Fix It option 1 and set audio trim to +4 dB on the Audial input (XLR-3). And voilá, all three DACs are now volume matched. I had stopped using the Audial, but not any longer!
I’ve never owned a preamp with audio trim capability, hence I didn’t even think to look for the feature. I’m not sure how prevalent this is among preamps, but the fact that PS Audio includes this feature is a huge bonus.
What were some of the negatives of using the BHK pre with the S200 amp?
I do regret saying this in a way that was perceived this way. Every design has a balances of design compromises. That’s not to say that it’s compromized. I think that wasn’t communicated well on my part. Lower sensitivity or demanding impedance/reactive load will benefit from the higher power of an S400.
But there it is, and it does have merit. After all the slightly higher class A output of the S200 does have its appeal for those that appreciate texture and subtlety in their music.
I thought the comments that Chris made regarding the difference between the S400 and the S200 were very helpful. Normally I would have thought the S400 would be better because it had more power. But Chris helped us to understand who would benefit the most from each amp. It might not be that more watts are always better. I have the FR 20’s and I’ll probably seriously consider the S200. I have a large room but I listen at moderate levels. I appreciate this level of clarity as to who would benefit from each amp. Thanks Chris!
I am driving FR20’s with the S200 and am quite pleased (M700’s going to fedex tomorrow). Room is 26 by 25 with 9 foot ceiling. PMG pre volume level 25-50 out of PMG DAC set at 100 fixed.
Or the M400…
Yes, I think my choice would be between the M400 and the S200. But I only listen to jazz and singer songwriter music and a little rock music I have to consider what would work for me. I am also using the PMG Preamp and the PMG DAC. I’ll be replacing the BHK 250 amp. Not sure I need the M400 for what I listen to.
Is not just for current, there is an imaging stability with monoblocks that is appealing.
I’d like to know more about imaging stability. I’m sure the M400’s are an improvement. I’m looking forward to some additional responses before I decide what to choose.
The M400’s are also 30 watts in Class A.
The S400 has the lowest wattage running in class A. So I’m curious how much that changes the presentation of the music listening at moderate levels?
Is there a noticeable difference between the S200 compared to the S400?
The S200 has 10 watts in Class A. The S400 5 watts in Class A. The M400 has 30 watts Class A. The M800 has 50 watts in Class A.
If you are seriously in the market possibly arrange a Boulder PSA demo. Put the questions behind you, and do bring cash. 