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Tannoy TS10 sub

P

Phil Allison

Jan 1, 1970
0
** I have a Tannoy TS10 in for repair.

The PSU switching FET (IRF740) is shorted so I expect the drive IC ( UC3842)
is also dead. There appears to be NO source resistor with the FET for
current sensing.

The PSU produces a *single* DC rail for the bridge mode amplifier of about
140 volts - there is a 1000uF, 160V electro. I guess the speaker outputs
rest at 0 volts and the DC rail electronically splits into +/- 70 volts.

Question is, how in hell are only four *puny* TO220 mosfets supposed to form
a bridged output stage and drive a 4 ohm woofer from such a supply voltage ?

Looks to me like a real piece of Chinese shit.



.... Phil
 
J

John Smith

Jan 1, 1970
0
Phil Allison said:
** I have a Tannoy TS10 in for repair.

The PSU switching FET (IRF740) is shorted so I expect the drive IC (
UC3842) is also dead. There appears to be NO source resistor with the FET
for current sensing.

The PSU produces a *single* DC rail for the bridge mode amplifier of about
140 volts - there is a 1000uF, 160V electro. I guess the speaker outputs
rest at 0 volts and the DC rail electronically splits into +/- 70 volts.

Question is, how in hell are only four *puny* TO220 mosfets supposed to
form a bridged output stage and drive a 4 ohm woofer from such a supply
voltage ?

This page says it uses something called BASH, which I'd never heard of.
http://www.samash.com/p/Tannoy_TS10 Active 10 Powered Studio Subwoofer_-49998207

After much googling I found this:
http://www.thompdale.com/bash_amplifier/bash_amp.htm

Which suggests it does something similar to the Yamaha XM6150 I currently
have waiting for parts.
I don't see why a 160V rail is needed though.

Old guy.
 
P

Phil Allison

Jan 1, 1970
0
"John Smith"
"Phil Allison"

This page says it uses something called BASH, which I'd never heard of.
http://www.samash.com/p/Tannoy_TS10 Active 10 Powered Studio Subwoofer_-49998207

After much googling I found this:
http://www.thompdale.com/bash_amplifier/bash_amp.htm

Which suggests it does something similar to the Yamaha XM6150 I currently
have waiting for parts.


** Thanks for going to all that trouble.

There is indeed a switching regulator on the main DC output and the scheme
is similar to the Klipsch one.



..... Phil
 
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