How do I down the volume on Blackstar FLY3?

[SushiMaster]

Hi guys.

I am a fan of Blackster FLY3.

It is a 3W amp but its too loud for the apartment I live in.

Specifically, I can only turn the volume knob turn to about 1. Its hard to adjust and its stressful for me

If I could turn down the max volume I could turn the volume knob as freely as I do when playing in the studio.

What modifications should I make?

In case you are wondering, I have enough skills to DIY pedals. If its not too hard to mod it, I will do it right away.

Please give me your advice.

[karul]

I've now finished tracing the Blackstar Fly3 practice amp. Was a bit more to it than I expected when I started
All the schematics are up on my website (see links below).
Here is a block diagram I drew up of the amp
Blackstar_Fly3_block_diagram.png

Probably more useful for everyone, here is an index of links to each schematic in some kind of sensible order (it is not in sensible order on my website )

Main PCB
Input stage. pre-amp, and clipping: https://static.ucraft.app/fs/ucraft/use ... 1609971056
EQ and Blackstar "ISF" tone-stack: https://static.ucraft.app/fs/ucraft/use ... 1604257987
Digital "Tape Delay": https://static.ucraft.app/fs/ucraft/use ... 1598721766
Mixer, headphone amp, and source switching: https://static.ucraft.app/fs/ucraft/use ... 1597009236
Power supply and filtering: https://static.ucraft.app/fs/ucraft/use ... 1606946210

Small PCB mounted on speaker
Power amp: https://static.ucraft.app/fs/ucraft/use ... 1594590407
The extension cab (for stereo) is just the same power amp board on a speaker in a box.

Discussion of bass ported speaker cabinet: http://www.midboost.com/workbench/black ... ase-design

Other PCBs in the amp
Pot and switch board: https://static.ucraft.app/fs/ucraft/use ... 1608304579
Extension cab connector / battery board: https://static.ucraft.app/fs/ucraft/use ... 1596058119

The web pages have lots more photos, SPICE sims, circuit analysis, and other info. See http://www.midboost.com/workbench/blackstar-fly-3 and http://www.midboost.com/workbench/blackstar-fly-3-pt2

Hope that all helps!!
And thanks for help with parts of the circuit on this thread

It seems that the volume pot is (20k) linear [look at the end of the EQ and Blackstar "ISF" tone-stack]. https://static.ucraft.app/fs/ucraft/use ... 1604257987

Changing it to log taper, should gave you better control. But be careful when desoldering, if you are not skilled enough or do not have proper tools you can easily damage the pcb. Or you may seek solution with volume pedal or something similar.

[bmxguitarsbmx]

You could install a resistor in series with the speaker.

[ansil]

Hey sushi I have this amplifier and I love it I do have one question do you think yours might be defective?
I only ask because I have 3 of them I had to get the Is cream one.
Even though I already owned a black one with the extension cab, And my girlfriend has the black one as well.
I live in a house now but I used to have an apartment with very thin walls and you could Not complaining about my amplifier on one at all.
matter of fact I had a very good relationship with my neighbors and I actually played my looper into my amplifier so I could determine what volume level I would need.
But even the downstairs neighbor couldn't hear mine on one.

I'm not doubting your claims I was just wondering if maybe yours is defective or if your walls are that thin but that you worried about the neighbors it might be time to use headphones.

Cheers

[SushiMaster]

It seems that the volume pot is (20k) linear [look at the end of the EQ and Blackstar "ISF" tone-stack]. https://static.ucraft.app/fs/ucraft/use ... 1604257987

Changing it to log taper, should gave you better control. But be careful when desoldering, if you are not skilled enough or do not have proper tools you can easily damage the pcb. Or you may seek solution with volume pedal or something similar.

Thanks for the detailed advice! I am going to disassemble my FLY3 on my next holiday.

.

[SushiMaster]

You could install a resistor in series with the speaker.

Yes, that is a simpler solution, but I was looking for another way.

By the way, what value of resistance do you think is appropriate?

.

[SushiMaster]

Hey sushi I have this amplifier and I love it I do have one question do you think yours might be defective?
I only ask because I have 3 of them I had to get the Is cream one.
Even though I already owned a black one with the extension cab, And my girlfriend has the black one as well.
I live in a house now but I used to have an apartment with very thin walls and you could Not complaining about my amplifier on one at all.
matter of fact I had a very good relationship with my neighbors and I actually played my looper into my amplifier so I could determine what volume level I would need.
But even the downstairs neighbor couldn't hear mine on one.

I'm not doubting your claims I was just wondering if maybe yours is defective or if your walls are that thin but that you worried about the neighbors it might be time to use headphones.

Cheers

I live in Japan.

Japanese housing is inadequate for sound insulation, and few houses, even single family homes, allow amps to be played loud enough.

I think it was inevitable that the YAMAHA Silent Guitar was born in this country.

.

[ansil]

Fair enough my friend

[bmxguitarsbmx]

You could install a resistor in series with the speaker.

Yes, that is a simpler solution, but I was looking for another way.

By the way, what value of resistance do you think is appropriate?

.

try a 47 ohm resistor. then put resistors in parallel until the volume is right

[Manfred]

You could install a resistor in series with the speaker.

Yes, that is a simpler solution, but I was looking for another way.

By the way, what value of resistance do you think is appropriate?

The solution with the resistor is not the easiest one.
The D-amplifier supplies a PWM signal at the output from which the audio signal is generated by the both symmetrical low-pass filter.
The values of this filters depend on the load impedance whose value must be taken into account during development.
The connection of a serial resistor could lead to unwanted effects.
Have a look at this publication:
https://passive-components.eu/optimizin ... t-filters/

[Tassieviking]

Try using the volume on the guitar.
Or throw some pillows or blankets over the amp.

[SushiMaster]

Try using the volume on the guitar.
Or throw some pillows or blankets over the amp.

The nostalgic way. I used to cover my amp with a Winnie the Pooh blanket.

[SushiMaster]

You could install a resistor in series with the speaker.

Yes, that is a simpler solution, but I was looking for another way.

By the way, what value of resistance do you think is appropriate?

The solution with the resistor is not the easiest one.
The D-amplifier supplies a PWM signal at the output from which the audio signal is generated by the both symmetrical low-pass filter.
The values of this filters depend on the load impedance whose value must be taken into account during development.
The connection of a serial resistor could lead to unwanted effects.
Have a look at this publication:
https://passive-components.eu/optimizin ... t-filters/

Thanks for your detailed advice. I have read the material you presented and several websites in Japanese.

I understand that a D-Class amplifier does not output a simple analog signal, but that is a bit difficult for me.

After all, is the easiest way to solve my problem the control improvement using Log-A as suggested by karul?

[ansil]

Took a look at it and took me a minute to find my copy of the schematic if you backed it up just a little bit you can change the one resistor. It is A47K resistor if you change it to like A22K it will Roughly = 1/2 of the output stage. R24