Author Topic: Let's talk about the Jordan Bosstone. An odd one...  (Read 12418 times)

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John Lyons

Re: Let's talk about the Jordan Bosstone. An odd one...
« Reply #40 on: January 09, 2011, 08:15:29 PM »
I'd like to order the part(s) needed to rid of any oscillations, should they arise (as they seem to be common).

Use low gain transistors. 200ish hfe or lower
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kinski

Re: Let's talk about the Jordan Bosstone. An odd one...
« Reply #41 on: January 09, 2011, 08:28:03 PM »
Right, 2n2222 and 2n3906 are under 200 hfe, yeah?

Also, will either of those layouts work? They seem to have differences. Like the 2.7k resistor, etc.

Thanks!

brett

Re: Let's talk about the Jordan Bosstone. An odd one...
« Reply #42 on: January 09, 2011, 09:16:44 PM »
Hi
modern 2N3906s are way over 200.  Even 2N2222s are too high for older circuits.
Try BD139s or other medium power (2 to 10W) devices instead of old small-signal transistors.  hFE around 150.  TIPs, MJEs, etc are also good.
cheers
Brett Robinson
Let a hundred flowers bloom, let a hundred schools of thought contend. (Mao Zedong)

mac

Re: Let's talk about the Jordan Bosstone. An odd one...
« Reply #43 on: January 13, 2011, 03:23:57 PM »
Quote
Just speculating on my part, but for fun follow this path and ignore the other components:

NPN collector, up the 18k resistor, stop.  Over to one side is a .022 cap to ground.  Turn left and head down the 560k resistor, stop.  Hey, another .02 cap to ground!  Continue heading toward the NPN's base along the next 560k resistor, then stop at the base.  With the input control grounded, why look!  There's another .02 cap to ground!  We got ourselves a phase-shift oscillator!

IIRC gain has to be above 29 for stable oscillations. Can you estimate maximun hfe to be below that limit?

mac

Dingus

Re: Let's talk about the Jordan Bosstone. An odd one...
« Reply #44 on: January 07, 2013, 05:19:03 AM »
Nashville version:



My apologies for the thread necromancy, but is that a 2n3565?  I hadn't seen a version that used that, maybe I just need to read up on this circuit some more.


skrunk

Re: Let's talk about the Jordan Bosstone. An odd one...
« Reply #45 on: January 07, 2013, 07:02:41 AM »
most likely.
from my notes the Nashville used a 2N3565 and a M924/95232, though there may have been other combos used(?).
the gains of 2N3565s can vary quite a bit though, mine go from hfe 150 to 600, so I'd make sure to use a low gain one if you use one.