BOZ: Replacement for tip29?

[KT]

What can I use instead of the tip29, which I understand has been discontinued?

Of the replacement options, which performs best sonically?

Thanks,
KT

[rpapps]

Hi KT
The TIP29 comes in seven varieties, each with different voltage ratings.
If yours are plain TIP29 or TIP29A, B or C try 2N6123 or BD589.
If they are D, E or F, I don't have a direct replacement listed.
Regarding their sonic performance, I have no knowledge.
Hope this helps.
Rob

[Kermit]

BD239 is what I use.

[rpapps]

OK, but the same thing applies. The BD239 also comes in seven voltage variants so you need to know what your supply voltages are.
Also, the hfe or current gain of the BD239 is lower than the TIP29 so you may not get as much output from it.
Cheers
Rob

[rpapps]

Hi KT
I've just looked in my supplier catalog and TIP29C is still available here in Oz for AUD$0.89. If you're interested, Ill pass on the details.
Cheers
Rob

[KT]

Thanks Rpapps,

Please do pass along the information. I'm using an Avel-Lindberg dual secondary 30V transformer in order to get the required 60V.

I haven't had a chance to look up the transistor specs. Would this tip29 work OK for this voltage? Or would I need another one of the units?

Thanks a lot,
KT

[Kermit]

Rpapps, I suppose you are right about hfe being lower on bd239. But I get the impression you think tip29 (it’s tip29c by the way) is the output device, but it’s part of the zener voltage regulator. Matching hfe isn’t necessary, as long as it can handle the dissipation.

[rcavictim]

At the risk of sounding like a BOZO, can someone please explain to me what BOZ. BOSOZ, etc. are? I gather they refer to a sand device or device topology(ies).

Hey, I only play with tubes.

[KT]

RCA,

BOZ_stand for "Bride of Zen". This is the Nelson Pass designed preamplifier which was meant to be mated with the original Zen amplifier.

BOSOZ stands for "Bride of Son of Zen", which later generation preamp. This was designed to mate with the "Son of Zen", which is a later generation Zen amp. Both the BOSOZ and the SOZ use a balanced topology.

All of these projects were designed by Nelson Pass and graciously bestowed upon the DIY community. These articles and designs were originally published in The Audio Amateur beginning in 1994 and then later in AudioXpress as the designs evolved.

From what I understand, many of these DIY designs aren't too far off of the topologies of Pass Labs' commercial offerings.

The articles and circuits can be found on www.passdiy.com.

KT

[rcavictim]

KT,

Thanx for the excellent explanation. I was searching for a fitting technical topological acronym and had gotten nowhere. I never would have guessed. Like I said. I play with tubes and have virtually no interest anymore in sand DIY for home audio.