Pre 1 preamp vs Topping Pre90

[Howard R]

Alan, I plan to visit the Sydney HiFi show to discuss the issue in the heading. I currently have the Topping Pre90 feeding into your small stereo amp and basically I am enthralled by the results I am getting via a pair of Legend Tripos 3 way bookshelf speakers from Dr Rod Crawford. It was Rod who recommended your amp to me.

Whilst I intuitively suspect that your new preamp will sit more comfortably with the amplifier, I would love to hear what you or others would say to convince me to replace the Topping Pre90 with your new preamp.

Any thoughts?

 

[Alan March]

Alan, I plan to visit the Sydney HiFi show to discuss the issue in the heading. I currently have the Topping Pre90 feeding into your small stereo amp and basically I am enthralled by the results I am getting via a pair of Legend Tripos 3 way bookshelf speakers from Dr Rod Crawford. It was Rod who recommended your amp to me.

Whilst I intuitively suspect that your new preamp will sit more comfortably with the amplifier, I would love to hear what you or others would say to convince me to replace the Topping Pre90 with your new preamp.

Any thoughts?

Surprisingly many pre amps have rather mediocre performance. However, the Pre90 is very good, probably one of the better performers out there.

In terms of fundamental noise and distortion performance, our Pre1 is a little better. It's also a different beast to the pre90

The Pre90 only has one input, unless you buy the extender box. It doesn't have a phono input. Pre1 has 3 inputs plus a MM phono input.

Of course our Pre1 is also an aesthetic match to our power amps.
 

Hope that helps

Alan

 

[Howard R]

Thanks Alan. I look forward to checking it out.

 

[Keith]

If you are only using digital sources, consider if you need a pre-amp at all.

I use to use a pre/power amp combination , then got a Dac with a volume control, 3 inputs and different voltage outputs to match different power amplifiers, and now use it as a pre-amp straight to the power amp. There was no deterioration in sound quality, and leaves you more money to spend on your other components.

 

[Alan March]

This is indeed correct and exactly how I set up my system. I only have one source, a DAC fed by Roon software, which directly drives the power amps. Volume can be controlled by the DAC or Roon software.

At the end of the day, whilst good pre amps are audibly transparent, they can only add additional noise, distortion and colouration.

Obviously no good if you need to switch between multiple sources where a pre amp is required.

 

[Howard R]

Hi Keith

I understand your point. In my case I am using an SMSL SU10 DAC which I have found to be most satisfactory for my needs, having inputs for my CD player, digital radio, computer etc. I then upgraded my amplifier to Alan’s lovely P262 with the lower gain setting as I was using XLR inputs from the DAC. I found that when I put the SMSL into preamp mode there were times when I just could not get the really high volume from the amp that I needed in those private moments when everyone is away and you want to lift the roof off. Perhaps having the gain in higher mode would have been ok but I decided to look at preamps in my budget area and after some research I found the Topping Pre90. I was pleased to hear Alan’s remarks about the Topping as I have found it very satisfactory and it also solved my volume issue as it seemed to drive the amp to a higher level than even with the SMSL at max.

The SMSL, to my understanding does not have variable settings for higher gain.

I am also now using a Matrix Element S streamer connected via I2S to the SMSL DAC as I have decided that Tidal integration and the ability to connect a USB hard drive for my local hires files has really completed what will be the 99% of my listening wishes. Like many people I gave away all my vinyls years ago and do not have the time or money to get back into that area.

At some point you/I have to be practical such a silly notion when there are so many things to buy.

In summary, I probably have one more box than I need, but each of the boxes I have, seems to be really good value for money and I am very happy that I can make Dr Rod’s speakers sound so good with Alan’s P262.

Thanks for your thoughts, I hope I have explained my situation.

 

[Keith]

Hey Howard,

Sounds like you've considered if you need a pre-amp, and you've decided you do, so it's the right decision for you. At the end of the day, it's all about enjoying our music, and the Topping pre-90 allows you to do that.

I remember when the pre-90 was released it received great reviews, and if I was buying a pre-amp it's the one I would have chosen also. Great price and great performance. I had a memory that the reviewer at Stereophile ended up buying one, but having looked at the review again he bought three!

Yes we have to be practical. Our system became too complicated to the point that my wife stopped using it, so I decided to start simplifying things, hence the Dac to power amp decision. Next is the speakers, from electrostatics and subs back to conventional speakers, then hopefully a matching power amp upgrade (I'll have a discussion with you Alan about that later in the year).

Keep enjoying the music Howard,

Keith.

 

[Howard R]

Hi Alan,

Very bad choice of time to come to the East to show off your wares I was flooded in on the Friday and Saturday and no trains running on Sunday so I missed the big show. Looking froward to seeing the reviews and discussion about the new gear. Climate change willing, I will try again next year.

 

[Laoman]

"Topping pre-90 allows you to do that." Beware of Topping's quality control. I would not touch that brand.

 

[Howard R]

This is indeed correct and exactly how I set up my system. I only have one source, a DAC fed by Roon software, which directly drives the power amps. Volume can be controlled by the DAC or Roon software.

At the end of the day, whilst good pre amps are audibly transparent, they can only add additional noise, distortion and colouration.

Obviously no good if you need to switch between multiple sources where a pre amp is required.

Alan, regarding the SMSL SU-10 DAC, I found that using it in preamp mode left me a bit wanting in top volume with the P262 amplifier. I had the gain set for XLR inputs. My model does not have the gain switch on the back and you set that up prior to delivery. If changing the gain to the high level allows me to get the extra volume I want in some cases (not very often), with the DAC, can I easily modify the gain level inside the amp myself? And secondly am I likely to notice any increase in noise at the higher gain given that currently, my ears detect virtually no background at all?

Regards,
Howard

 

[Alan March]

Alan, regarding the SMSL SU-10 DAC, I found that using it in preamp mode left me a bit wanting in top volume with the P262 amplifier. I had the gain set for XLR inputs. My model does not have the gain switch on the back and you set that up prior to delivery. If changing the gain to the high level allows me to get the extra volume I want in some cases (not very often), with the DAC, can I easily modify the gain level inside the amp myself? And secondly am I likely to notice any increase in noise at the higher gain given that currently, my ears detect virtually no background at all?

Regards,
Howard

Hi @Howard R

I'm a little surprised by this as the su10 outputs up to 5.1 volts. The P262 actually gets to full output a bit below 4 volts input, so even with "quiet" recordings you should be able to get it to Max.

Excuse my stupid question, but are you using xlr from the su10 and not its rca outputs?

If you have one of the newer buffer boards in the p262 it's a simple jumper to change the gain which you can do yourself. Older boards were fixed and the amp would require returning for modification.

Unless you have massively sensitive speakers you are very unlikely to hear any hiss even at the higher gain setting.

Alan

 

[Howard R]

Hi @Howard R

I'm a little surprised by this as the su10 outputs up to 5.1 volts. The P262 actually gets to full output a bit below 4 volts input, so even with "quiet" recordings you should be able to get it to Max.

Excuse my stupid question, but are you using xlr from the su10 and not its rca outputs?

If you have one of the newer buffer boards in the p262 it's a simple jumper to change the gain which you can do yourself. Older boards were fixed and the amp would require returning for modification.

Unless you have massively sensitive speakers you are very unlikely to hear any hiss even at the higher gain setting.

Alan

Thanks for the super quick reply Alan. Yes I was using XLR between the SU10 and the amp. Perhaps I should recheck the set up as it was some time ago now. I will test again tomorrow and maybe I'll have a Pre90 excess to requirements and available for sale BTW my order was placed in March 2023, so that may identify whether the board is of the newer type with a jumper.

 

[Alan March]

I would expect this to be a newer board with jumper in that case. I will post details on how to change the gain later.

 

[Howard R]

Alan, i have just done a test with the SU-10 and things are as you predicted in terms of volume. I can only think that when I did the original listening I chose some very softly recorded music. It was also at a time when I had 15 m of XLR cable from the SU-10 to the amp. Whether there was a significant loss over that distance, maybe depends on the quality of the cables. I now have amp and inputs very close to each other and to the speakers. All seems good with the low gain setting on the amp so I don’t think I need to make any changes there either. Just listening to Prokofiev violin concerto via Tidal and my Matrix Element S streamer into SU-10 and at -6dB on the DAC volume is as high as I want for the loud bits. Thanks for the feedback and opportunity to discuss via the forum.

 

[Alan March]

Hi, glad it's sorted. Just to mention that you won't get any appreciable loss of signal over long xlr cables, that's one of the benefits of long inerconnects over long speaker cables.

Cheers

Alan

 

[Ash]

Hi Alan,

I’m of course no expert on these matters, but my reading suggests that using the digital volume control on my intended Gustard X26 III DAC, driving a P282 directly, would reduce bit depth by truncating digital data, especially at lower volumes, thus degrading resolution, dynamic range, and low-level detail. Is this not the case?

Cheers,

Ash

 

[Alan March]

Hi Alan,

I’m of course no expert on these matters, but my reading suggests that using the digital volume control on my intended Gustard X26 III DAC, driving a P282 directly, would reduce bit depth by truncating digital data, especially at lower volumes, thus degrading resolution, dynamic range, and low-level detail. Is this not the case?

Cheers,

Ash

Hi @Ash

There is a bit of a misunderstanding generally about how digital volume controls work. I cant comment specifically on the Gustard as I dont know how its implemented, but here is a general comment.

The calculations for a digital volume control should be performed at higher bit depth than the actual recording you are playing, so 32 or 64 bit. I use Roon software and it uses 64 bits.

Doing this means that no resolution is lost. For info 16 bit has 65535 signal levels, 24 bit has 16,777,215 levels, 32 bit has 2,147,483,647 levels and 64 bit has 9,223,372,036,854,775,807 levels.

Also it should be noted that real world recordings simply dont acheive 24 bit resolution (SNR). 18 to 19 bit is about the best you will find.

Also that real world noise levels in the best electronics (dacs, surrounding amp circuitry etc) only reaches about 22/23 bit.

So "resolution" is a non issue with digital volume.

A real theoretical disadvantage of digital volume is as follows.

All electronics have a level of noise. A DAC will produce a certain level. When using a "perfect" analogue volume pot, when you turn it down both the music signal level *and* the inherent background noise of the source will turn down also. As such in theory it will maintain the signal to noise ratio.

Using a digital volume, when you turn it down the music signal level decreases but the inherent source background noise remains the same. As such signal to noise ratio decreases.

So that's a real theoretical disadvantage. Now let's step back into the real world.

Source electronics noise levels are now so low that this potential disadvantage is irrelevant. DACs are around 130dB SNR. The noise is completely inaudible and then some.

Analogue volume controls aren't perfect. They will *always* be noisier. They will have issues such as balance tracking (although much better with stepped ladder).

Power amplifiers will be the noisiest part of any signal chain as they have a lot of gain to raise the source signal to levels able to drive speakers. The power amp will be the limiting factor in most systems.

So, all the concerns about digital volume controls are moot in a real world system. If properly implemented they will always perform better than an analogue control.

The only reason to have a pre amp is if you have multiple sources (dac, streamer, turntable etc) and need to switch between them. Otherwise a DAC/streamer run directly into a power amp will perform better.

Just an aside, when recording and mixing music these days in the studio, A DAW (digital audio workstation) is usually used. The mixing volume level changes for each instrument is done with 64 bit digital volume control.

In conclusion, dont be concerned in any way about digital volume control. I would always use it in preference to analogue.

Hope that helps

 

[Alan March]

Hi @Ash

I've looked at the Gustard, its a good performer and I wouldn't hesitate to use its own own volume control.

 

[Holmz]

…

Power amplifiers will be the noisiest part of any signal chain as they have a lot of gain to raise the source signal to levels able to drive speakers. The power amp will be the limiting factor in most systems.

If we are talking about distortion, then ^this^ is 100% not true.
If you are talking solely about noise, then maybe you;re correct… but unless one is putting their melon next to the tweeter, the noise is largely inaudible.

For distortion then maybe a SET amp with your speakers playing low, has the amps as the highest distortion in the chain.
But in general the speakers dominate distortion by orders of magnitude.
And certainly with any amp that is decent the speakers with distortion at say -30dB totally dominate.
If they are being played low and with distortion around -60, then still most decent amps have THD+N below -70dB.

So, all the concerns about digital volume controls are moot in a real world system. If properly implemented they will always perform better than an analogue control.

Or at least well enough.
But a good preamp is also just dandy.

The only reason to have a pre amp is if you have multiple sources (dac, streamer, turntable etc) and need to switch between them. Otherwise a DAC/streamer run directly into a power amp will perform better.

^I abide.^

Just an aside, when recording and mixing music these days in the studio, A DAW (digital audio workstation) is usually used. The mixing volume level changes for each instrument is done with 64 bit digital volume control.

In conclusion, dont be concerned in any way about digital volume control. I would always use it in preference to analogue.

Hope that helps

^100%^

 

[Alan March]

If we are talking about distortion, then ^this^ is 100% not true.
If you are talking solely about noise, then maybe you;re correct… but unless one is putting their melon next to the tweeter, the noise is largely inaudible.

Erm...well...yes, I 100% agree. Speakers are horrible in terms of disrortion compared to electronics. However, we were talking specifically about noise. In this context, the speaker distortion issue applies just the same to analogue and digital volume controls.

Also it should be noted that amplifier noise becomes a very real audible issue when using high sensitivity speakers < 100dB such as horns.

Or at least well enough.
But a good preamp is also just dandy.

No, correctly implemented digital volume will beat a simple analogue control every time. A hybrid control can be used to optimise SNR (see RME DACs), but that's not the case with typical pre amps.

Whilst the best pre amps are audibly transparant, there are a lot of pretty mediocre ones out there. Essentially, even the best pre amp can only add to noise, distortion and colouration. If you only have one source, i.e a DAC/streamer, then dont use a pre amp.