Problem with low volume/gain using S300 amp with a Ladder Bach DAC

I purchased an S 300 amplifier. I am using it with a ladder Bach preamp. For the moment, I’m connecting it with RCA connectors but plan on using XLR eventually. Bottom line is I’m getting very little volume out of the set up. I mean, I turned it 2/3 volume and still not much that should blow me out the room. With my old Integrated if I turned it halfway up, that was as loud as I ever used it.

2/3 volume and still not much that should blow me out the room. With my old Integrated if I turned it halfway up, that was as loud as I ever used it.

Any ideas?

Welcome!

did you or your friend have a preamp to lend you for testing?, i used it with a passive preamp and it was amazing result, very musical and more base than my previous preamplifier. and now with a M7 clone, it is just musical and plenty of power!

maybe impedance from preamp is not wright for S300, one must be down and the other must be up, if i remember correctly.

but first try it with another preamp, a friend preamp, so you will have a third wheel investigation on what’s wrong!

keep us inform!

best regards

ps, be carefull, some XLR are not really XLR

How do I know whether the impedance is right for the preamp?

When matching preamps to power amps, a general rule of thumb is for the load (amp) input impedance to be at least 10 times higher than the source (preamp) output impedance to provide a suitably flat frequency response. Many prefer using a minimum ratio closer to 20 to 1, or having an amp with input impedance 20 times or more greater than the preamp output impedance.

from this forum:

rule of thumb, from Agon

you have the spec, so read them, and verify it!

here are the specs, pretty sure the impedance ratio is fine and not the issue but pls review

Input: IN1-XLR IN2-XLR IN3-RCA
Input Impedance: Single-Ended 12.2K Ohms Balanced-60K Ohms
Output: RCA at 2.0Vrms XLR at 4.0Vrms
Output Impedance: Single-Ended 200 Ohms Balanced-400 Ohms
Gain: Unity Gain,0dB
AC Power Requirement: 100-240VAC,50/60Hz(Worldwide Voltage)
Frequency Response: 10-80k(-0.3dB)
THD+N: 0.00%
S/N Ratio: 120dB
Dynamic Range: >121dB
Stereo Crosstalk: -110dB

here are the specs, pretty sure the impedance “ratio” is OK

Input: IN1-XLR IN2-XLR IN3-RCA
Input Impedance: Single-Ended 12.2K Ohms Balanced-60K Ohms
Output: RCA at 2.0Vrms XLR at 4.0Vrms
Output Impedance: Single-Ended 200 Ohms Balanced-400 Ohms
Gain: Unity Gain,0dB
AC Power Requirement: 100-240VAC,50/60Hz(Worldwide Voltage)
Frequency Response: 10-80k(-0.3dB)
THD+N: 0.00%
S/N Ratio: 120dB
Dynamic Range: >121dB
Stereo Crosstalk: -110dB
Warranty: 12Months

Hi,

with respect and reserve, test it with another preamp and ask a pro, about it. PS offer great customer services, maybe a call to them, would help more.

S300 is: Input impedance - Unbalanced 50KΩ and Balanced 100KΩ

Mine on Ali it is: Remote ALPS RK27 Passive Volume Controller Passive Preamplifier 10K 50K 100K my choice to choose impedance when ordered. Mine passive preamp: when ordered for my Linn LK2 was 10k, but i had the choice to 50k and 100k. It will be my transitory passive preamp, until i have stack enough money for a PS preamplifier.

Simple Passive Preamp I have a 1/5 ratio, that is Ok, but not the best

your preamp is: Input Impedance: Single-Ended 12.2K Ohms Balanced-60K Ohms.

Ladder II, info i have found, so it would be 200/50 or 100 depending if you are using XLR

I am not a technician, and you better go with a pro, on this one. My S300 play flawless, even with a M7 clone with 12ax7 tube that i have.

here the Master explaining:

Master Paul explaining Matching Amp & Preamp

and this is my limit to help, could go further on explanation, I learn more everyday, from the last 50years!

It’s also unity gain - preamps that aren’t passive will have typically have more gain.

and an active preamp will have ticker mid and high, but for transitory my passive will do for me, and the s300 kick the bass, more than my previous preamp with my passive!

so rule of thumb, low to high for preamp to amplifier!

how much more? compared to my musical fidelity A300 integrated I am getting less than half the volume with the S300

Hi

with respect, the only musical i had was the A1 Pankake toaster, kid burn his tiny hand and cat learn to don’t mess with HiFi, so could not help you. And i never listen loud, sorry could not help.

have you check the Paul Video?

maybe go to the store who sold it to you and have it check

Sorry

Integrated amp functions differently because of their integrated volume control. It is not easy to compare directly.

your preamp is able to produce 2Vrms output, and the psaudio should be driven to full power with 1Vrms. That means your preamp is able to ip the psaudio amp.

Also, below the 0dB point? The preamp is only attenuating what comes from the source. What sources are you using?

I have a Cd transport and a music stream running through a DAC

OP, Just a thought, could you have some sort of setting like ‘dac mode’ or ‘HT bypass’ or something like that accidentally on on your new preamp? Something that could defeat the volume or gain on the preamp? Does the pre have both ‘line level’ and ‘pre amp’ outputs? Are you sure youre plugged into the correct outs? Are you using high quality cables? Could those be bad?

I’m sure a call to PS Audio would help troubleshooting.

2 Likes

Half the volume is only 3db. I remember years ago back in the ‘70s I was using a 50wpc Luxman integrated to drive my large speakers. I wanted louder and bought a 120wpc Marantz power amp, feeding it from the preout of the Luxman intergrated. I still wasn’t happy so bought a Luxman preamp that went to 7volts output. That solved the problem. Whatever the source is, a unity gain preamp will only ever cut the volume so you’d need the volume control at maximum not to cut the volume.

Could you share the models of your sources?

another point: regardless where you have to put the dial of the volume setting, does your system get enough SPL?

Yeah, I just found out that my preamp has Unity gain so it doesn’t work with the S 300. My question is what kind of amp would work with a unity gain Preamp? The S 300 is what I would consider a Pretty “ Standard” power amp, so what kind of power amp would work with a unity gain preamp?

So I did borrow a preamp and that solved the Problem are I would say the mystery as to which component I was having issues with. What I found out is that this preamp I have is a Unity gain preamp. It doesn’t increase the volume can only decrease the volume. But I don’t understand is what kind of power amp do you use with a Unity preamp? I mean Are therepower amps with volume controls on them. I’ve got an email into PS audio. They are the ones who made me aware that this is a Unity gain preamp. I’m gonna end up sending it back unless The distributor can give me some ideas as to how it would make it work with this power amp. I’m just kind of flabbergasted that I could buy a standard power amp and what I thought was a standard preamp and did not work together. That’s crazy.