questions on boost circuit

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arjepsen
Posts: 221
Joined: Tue May 20, 2008 10:30 am

questions on boost circuit

Post by arjepsen »

Hey.
I'm looking over the boost circuit that 665 amps are using on several of their circuits.
The level control is a 6 way switch with resistors. I wonder why they choose to use this, instead of simply a 500k pot? To me it seems that would be a much easier / cleaner way. So why go through the trouble with the switch? What am I missing?
I've attached a schematic I found, where the boost circuit is shown with a pot instead.
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frankdrebin
Posts: 131
Joined: Wed May 14, 2014 11:40 am

Re: questions on boost circuit

Post by frankdrebin »

i have followed almost any YT video by Dan Boul of 65amps,its clear to me that he collected lots of infos around on forums,techs,personal vintage amps.
But in the end,without formal knowledge on electronics,its just a lot of popular beliefs,and his mantra is that whatever he puts in his amps its the best because it costs 4 times the average good part.
So if you put a rotary switch plus resistors and handwiring labor,all of that could be perceived as a secret technology,that in fact is called Bump and they got a trademark for it,instead of putting in a simple pot with 2 wires that looks silly.
Reminds me a lot of R. Smith,with his patents.

The other secret they have is the Master voltage,which in fact is the VVR by Hall.
oj
Posts: 79
Joined: Thu Mar 30, 2006 8:47 pm
Location: Sweden
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Re: questions on boost circuit

Post by oj »

frankdrebin wrote:i have followed almost any YT video by Dan Boul of 65amps,its clear to me that he collected lots of infos around on forums,techs,personal vintage amps.
But in the end,without formal knowledge on electronics,its just a lot of popular beliefs,and his mantra is that whatever he puts in his amps its the best because it costs 4 times the average good part.
So if you put a rotary switch plus resistors and handwiring labor,all of that could be perceived as a secret technology,that in fact is called Bump and they got a trademark for it,instead of putting in a simple pot with 2 wires that looks silly.
Reminds me a lot of R. Smith,with his patents.

The other secret they have is the Master voltage,which in fact is the VVR by Hall.
I agree with everything you are saying except for that in fat .

It is a Kevin O Conner design and not Hall design.
frankdrebin
Posts: 131
Joined: Wed May 14, 2014 11:40 am

Re: questions on boost circuit

Post by frankdrebin »

Hall sells a kit which is like that,KOC sells much more complicated kits.
Anyway nobody can claim invention of that basic design which is in textbooks and datasheets.
arjepsen
Posts: 221
Joined: Tue May 20, 2008 10:30 am

Re: questions on boost circuit

Post by arjepsen »

I could be wrong, but I don't think the VVR is Kevins design. I belive he would have patented or trademarked it in that case?
But as I stated, I could be wrong.

But back to my main curiosity - I wonder why they used the switch instead of a pot.
Looking over gutshots and layout, it seems they generally have a quality/durability oriented focus, although here and they I find solutions that can seem a bit like "quick fixes". However this makes it a bit hard to explain that particular switch.
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