Babelfish XA252 / Babelfish XA252 SIT / Babelfish XA252 SET

Disabled Account
Joined 2019
Hi,

I know nothing about amp, but I find seductive the idea of emulating these NLA SIC transistors with avialable parts for poor papys.

Is it stable till 3 ohms load ?

I have a stupid question I'm sure : is is possible with the complementary version to make instead a ciclotron layout with the same power transistor for M2 and M3 (on the shematic) still to have the watts but being closer of a class A ?

Could be my first Papa / ZM (aka Batman / Robin amp gang:devilish:) diy amp...:unsure:
 
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Official Court Jester
Joined 2003
Paid Member
Hi,

I know nothing about amp, but I find seductive the idea of emulating these NLA SIC transistors with avialable parts for poor papys.

Is it stable till 3 ohms load ?

I have a stupid question I'm sure : is is possible with the complementary version to make instead a ciclotron layout with the same power transistor for M2 and M3 (on the shematic) still to have the watts but being closer of a class A ?

Could be my first Papa / ZM (aka Batman / Robin amp gang:devilish:) diy amp...:unsure:


stable with any load, as long you are taking in account that party-breaker is acting around 10A of current through OS

that's role of two optocouplers and triak - to clamp/kill biasing of OS when set current is achieved

circuit in question xeroxed from Papa's Real McKay

now, clarify your question about circlotron ?

I'm not following you there ....

and, this amp is ( as all amps with OS arranged in Square Law) having extraordinary deep A Class

for instance - Babelfish M25 , which is Square Law iteration of beloved FW M2 ..... both B. M25 and FW M2 are having full A Class envelope @8R load - around 25W (limited with rails, not Iq)

now, M2 is 50W@4R jobbie, but "only" 12W5 of that being in Class A ......... and B. M25 is having same max power @4R, but 40W of those being still in Class A (both OS parts still conducting)

same behavior here
 
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Disabled Account
Joined 2019
After reading the sound Guide design of Pa's amps, we definitly need one for yours.

At least the XA 252 which looks to be a garou but vamp emulated seems fine with non high efficenty starving loudspeakers. I was thinking 2 years ago to a BA3 because of something between the FW F5 control and a J2 more SET character (from reading as having heard none)
 
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We're all waiting ... like salivating Labradors ...

waiting.jpg
 
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