No balance adjustment on Pre90.
-
Welcome to ASR. 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!
Topping Pre90 Review (preamplifier)
- Thread starter amirm
- Start date
Roland68
Master Contributor
The A90 Pro can also be expanded with the EXT90...
Very handy for my turntable and DAC inputs.
staticV3
Grand Contributor
- Joined
- Aug 29, 2019
- Messages
- 15,049
- Likes
- 26,431
Yeah, that's the tolerance.
This pre has been at the center of my setup for four years now and been flawless.
staticV3
Grand Contributor
- Joined
- Aug 29, 2019
- Messages
- 15,049
- Likes
- 26,431
Oh wow that's misleading.
I totally thought that's the range and step size in which one can adjust the L<->R balance
- Joined
- May 26, 2021
- Messages
- 693
- Likes
- 1,018
FWIW Dept.: Apparently these preamps do not support AES48.
Look at the doubled output level of the balanced outputs. If they supported AES48 (the balanced line standard) the output levels would be unchanged from single-ended.
To drive a balanced line properly you can't simply have two single-ended outputs that are out of phase with each other. The reason is in a proper balanced connection, ground is not used as a signal return. It is for shielding only. This practice prevents ground loops and reduces noise in the interconnect. It also insures the maximum CMRR at the receiving end. Therefore dual out of phase outputs cannot be used as they reference ground.
These things can lead to measurable and audible degradation.
The measurements shown should include a dBm output level since using a bit of power into a low impedance is also a common practice in balanced lines to prevent degradation of the signal across long cable lengths, although the benefit of a properly set up balanced line can be realized even if the connection is only six inches. The output impedance suggests this is not a problem. But if a coupling capacitor is present at the output, the output impedance at 20Hz will likely be quite a lot higher than at 1KHz.
Also, if the use of the device is for a proper balanced line setup, the distortion, separation, Voltage swing and bandwidth really should be measured into a low impedance, such as 1000 Ohms. 0dBm is defined as 1 milliWatt into 600 Ohms.
misterdog
Addicted to Fun and Learning
- Joined
- Dec 7, 2018
- Messages
- 760
- Likes
- 689
There's always the Benchmark HPA4 preamp which does adhere to AES 48, it even has a balance control.
If people think it might 'sound' better for $3,500.
I also think the optional remote control for $100 would work better than the Topping one.
Nice to have a choice for considerably less though.
Last edited:
40th Anniversary
Active Member
- Joined
- Oct 17, 2022
- Messages
- 209
- Likes
- 131
Check input impedance. I don't see it listed. I think the Pre90 has a paltry 2 kOhm input impedance.....
TheUncouthIndian
New Member
None... the Pre90 also does not have a 12V trigger, nor a ground lift switch.
The only reason I got the Pre90 is the nagging feeling of a potential "-5" error in the future, and I don't really need a headphone amp. I had previously got the the A90 Discrete, and got the "-5" error on the first power-on, and returned it and got the Pre90.
The Pre90, A90 Discrete, and the A70 Pro are the only devices that appear to accept the Ext90.
misterdog
Addicted to Fun and Learning
- Joined
- Dec 7, 2018
- Messages
- 760
- Likes
- 689
The Pre 90 is designed as a preamp with 6 inputs available (4x XLR 2x RCA) , each with volume limiters to avoid medical episodes when switching between them.
The L70 is designed as a headphone amp with only one input each of XLR and RCA.
If you use headphones, option B is more suited, if you have multiple sources option A.
They both have superb output voltages available at 17V allowing them to drive a Topping B100 power
amp with 0dB gain.
Which is my use case to drive Quad 989 ESL's.
Both are state of the art devices with any slight difference in specs being inaudible to anything bar a bat.
misterdog
Addicted to Fun and Learning
- Joined
- Dec 7, 2018
- Messages
- 760
- Likes
- 689
Rather than raising speculation, Topping are very amenable to an email to verify any technical queries.
Pre90 is older than L70, it can explain the higher price tag, then the technical solutions used there where shrinked down (like Topping PA5 to mini300, kind of)
Impedance values from this thread
www.audiosciencereview.com
Impedance values from this thread
Topping L70 Headphone Amp Review
This is a review and detailed measurements of Topping L70 balanced headphone amplifier. It was sent to me by the company and costs US $349. The L70 has the beautiful white segmented display. It is the most visible/high contrast display I have seen on an audio product. Volume control is very...
www.audiosciencereview.com
| Model | SE | BAL |
| Topping A90 | 10k Ohms | 2.0k Ohms |
| Topping A90D | 10k Ohms | 2.0k Ohms |
| Topping Pre90 | 10k Ohms | 2.2k Ohms |
| Topping L30 | 2.5k Ohms | N/A |
| Topping L70 | 2.0k Ohms | 2.0k Ohms |
Last edited:
As others have pointed out, you can enjoy great headphone performance with up to six inputs with A90 Pro or Discrete or A70 Pro as well; it (A70 Pro) just doesn’t look nearly as nicely matched to Ext90, but it does have the connection for it.
Exactly which repeater is that? I like how minimalist it looks in all-black.
On amazon.de it is available https://www.amazon.de/dp/B0716T6ZR8
On the US site currently unavailable https://www.amazon.com/dp/B0716T6ZR8
However, there are many that are essentially the same product. Like this one https://www.amazon.com/dp/B07NK74M5R where the receiver has a different color in the figures, but it is in fact quite deep dark red also in mine. I guess the difference is just ambient lighting and/or post processing.
This one seems to be the same as mine https://www.amazon.com/dp/B0F5MBND61
Similar threads
