• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. 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!

Fosi Audio TB10D Amplifier Review

Rate this amplifier:

  • 1. Poor (headless panther)

    Votes: 18 7.0%
  • 2. Not terrible (postman panther)

    Votes: 74 28.8%
  • 3. Fine (happy panther)

    Votes: 135 52.5%
  • 4. Great (golfing panther)

    Votes: 30 11.7%

  • Total voters
    257

mctron

Active Member
Joined
Apr 24, 2020
Messages
100
Likes
175
Hi All,

I have a single rear speaker presently powered by a Dayton APA150. I am going to order one of these FOSI's and compare. Was encouraged by my wife to try it based on the much smaller size. This single rear is in our living room behind the couches and anything that hides some electronics is favorable to her. So who am I to argue in trying new gear out especially when it can be returned to amazon. Got it for $59 plus tax after coupon.

Anyone have an opinion on what I will expect with this vs a bridged APA150?

Thanks
It will functionally be the same but be smaller and use less power
 

Mustang

Member
Joined
Dec 7, 2021
Messages
18
Likes
3
It will functionally be the same but be smaller and use less power

Well, overall the Fosi was ok but the noise floor was much worse than the Dayton APA150. I think the power supply on the Dayton might be superior. There is a hiss from the tweeter on both that's probably acceptable but the woofer was making a hum from the Fosi that isn't there on the Dayton that was unacceptable and the reason I'm returning it. Not sure if I got a dud and it's worth trying another or I might just stick with the Dayton.

A bit dissapointing. Any recommendations are welcome.
 

kiwipaul

Member
Joined
Jan 10, 2022
Messages
12
Likes
1
Bypassing the tone controls

Greetings. I have a Fosi Audio TB10D on order. I secured it for a good price but I want to have the option of bypassing the tone controls.

It seems to me I could replace one of the tone control potentiometer to add one with a built in switch, then use something like this audio relay to bypass the tone controls.

Any thoughts?

Aliexpress - Ultra-small Double Pole Double Throw Polarity Relay Module Mini

On reflection, what might be better is to use the switch on the potentiometer as the power switch, and adapt the existing power toggle to enable the tone defeat...
 

Kimbrough Xu

Active Member
Joined
May 18, 2022
Messages
192
Likes
79
Bypassing the tone controls

Greetings. I have a Fosi Audio TB10D on order. I secured it for a good price but I want to have the option of bypassing the tone controls.

It seems to me I could replace one of the tone control potentiometer to add one with a built in switch, then use something like this audio relay to bypass the tone controls.

Any thoughts?

Aliexpress - Ultra-small Double Pole Double Throw Polarity Relay Module Mini

On reflection, what might be better is to use the switch on the potentiometer as the power switch, and adapt the existing power toggle to enable the tone defeat...
Seems like you don't need the tone controls?

Why not just got the Fosi Audio V3 https://www.fosiaudio.com/product/2-channel-amplifier/v3/?
 

Fosi Audio

Active Member
Audio Company
Forum Donor
Joined
Sep 10, 2021
Messages
288
Likes
1,136
Bypassing the tone controls

Greetings. I have a Fosi Audio TB10D on order. I secured it for a good price but I want to have the option of bypassing the tone controls.

It seems to me I could replace one of the tone control potentiometer to add one with a built in switch, then use something like this audio relay to bypass the tone controls.

Any thoughts?

Aliexpress - Ultra-small Double Pole Double Throw Polarity Relay Module Mini

On reflection, what might be better is to use the switch on the potentiometer as the power switch, and adapt the existing power toggle to enable the tone defeat...
Do you mean you want the tone controls but also want the bypass function?

Can you let me know why?
 

Talisman

Addicted to Fun and Learning
Forum Donor
Joined
Mar 27, 2022
Messages
897
Likes
2,547
Location
Milano Italy
Do you mean you want the tone controls but also want the bypass function?

Can you let me know why?
this is simple. Tone controls may be useful in certain situations, but when they are not needed any audiophile wishes they could bypass those circuits.
Almost all historical amp brands have implemented the "direct" button which bypasses the tone control circuits, I'm surprised you don't know about it @Fosi Audio
 

restorer-john

Grand Contributor
Joined
Mar 1, 2018
Messages
12,581
Likes
38,283
Location
Gold Coast, Queensland, Australia
Do you mean you want the tone controls but also want the bypass function?

Can you let me know why?

Amplifiers and preamplifiers have had tone controls and bypass switches for 50 years.

Flatter response, better noise and lower distortion when bypassed and useful control when in circuit.
 
Last edited:

Doodski

Grand Contributor
Forum Donor
Joined
Dec 9, 2019
Messages
20,752
Likes
20,771
Location
Canada
Amplifiers and preamplifiers have had tone controls and bypass switches for 50 years.

Flatter response, better noise and lower distortion when bypassed and useful control when in cicuit.
Yes... it sounds wayyy better with tone controls... :D
 

Doodski

Grand Contributor
Forum Donor
Joined
Dec 9, 2019
Messages
20,752
Likes
20,771
Location
Canada
This commentary brings up a intriguing question. How much would it cost at wholesale cost and retail cost to add a couple of op amps, maybe buffers and pots to make tone controls?
 

restorer-john

Grand Contributor
Joined
Mar 1, 2018
Messages
12,581
Likes
38,283
Location
Gold Coast, Queensland, Australia
This commentary brings up a intriguing question. How much would it cost at wholesale cost and retail cost to add a couple of op amps, maybe buffers and pots to make tone controls?

Schiit make a standalone tone control IIRC.

At the peak of the cost cutting in the 80s, tone controls were put in the NFB loop of the power amp stages for many of the big brands to keep costs down at the low end. Not my idea of superior design, but it worked. Basically someone said, why build a standalone Baxandall feedback active tone control up front of the power stage when we already have the guts of of it already?

This is actually a PM-640 HK integrated from about 1983/4. An otherwise very nice amplifier.

1682754046569.png
 
Last edited:

Fosi Audio

Active Member
Audio Company
Forum Donor
Joined
Sep 10, 2021
Messages
288
Likes
1,136
this is simple. Tone controls may be useful in certain situations, but when they are not needed any audiophile wishes they could bypass those circuits.
Almost all historical amp brands have implemented the "direct" button which bypasses the tone control circuits, I'm surprised you don't know about it @Fosi Audio

Yes, I know.

I just confused if one wants the tone controls, why bypass them. That's why we have TB series (TB10A, TB10D) and V series (V1.0, V3) .
 

Doodski

Grand Contributor
Forum Donor
Joined
Dec 9, 2019
Messages
20,752
Likes
20,771
Location
Canada
Schiit make a standalone tone control IIRC.

At the peak of the cost cutting in the 80s, tone controls were put in the NFB loop of the power amp stages for many of the big brands to keep costs down at the low end. Not my idea of superior design, but it worked. Basically someone said, why build a standalone Baxandall feedback active tone control up front of the power stage when we already have the guts of of it already?

This is actually a PM-640 HK integrated from about 1983/4. An otherwise very nice amplifier.

View attachment 282245
That's very sneaky design work on the HK schematic. I like it. Are there advantages or disadvantages for performance using this method? :D Wonderful nice dark schematic.
 

kiwipaul

Member
Joined
Jan 10, 2022
Messages
12
Likes
1
Yes, I know.

I just confused if one wants the tone controls, why bypass them. That's why we have TB series (TB10A, TB10D) and V series (V1.0, V3) .
It is preferable to have both so you have the option of using the tone controls, or bypassing them. Amplifiers sometimes have relays to bypass the tone section of a preamp stage.

Something like this would work.

 

OpticonPrime

Member
Joined
Mar 23, 2023
Messages
14
Likes
13
Location
Netherlands
@Fosi Audio
What is the powerconsumption in standby?

And a feature request: make a on/off/auto switch function.

I am looking for a "light" (4 Dayton Puck mini) basshaker amp is Fosi the way to go?
 

Kimbrough Xu

Active Member
Joined
May 18, 2022
Messages
192
Likes
79
Auto is a great idea. My partsexpress Sub amp has Auto. When it detects an audio signal, it turns on. After X seconds of no audio, it goes back to standby.

Doesnt it consume too much power when standby?
 

GrayA

Member
Joined
Apr 26, 2023
Messages
35
Likes
11
Doesnt it consume too much power when standby?
Not sure, the manual says "When the power switch is in the auto on position, the amplifier will automatically turn
on when a signal is present. Note: In auto on/off mode, the Power On LED is always
on, even when the amp is in rest mode (off)."

 
Top Bottom