I would imagine for flexibility of placement. A single PCB for this would limit construction options.
For AFE & OPS, its because, that is the way Bob wanted it to be done. He also wanted them to be mirror imaged too.
Actually he wanted all three on the same Heatsink, AFE, OPS and Protection, it wouldn't fit on the 300mm HS
There are pros and cons to this arrangement
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Hi Guys
BC-1 is the same as Fig.3-13 in the 1sr edition, with all the "finesse" parts added (base-stops for output devices, better bias reg, etc). In the demo version the amp is the usual asymmetric input stage with current-mirror, feeding an EF-improved TIS, then an EF3 with 4-poairs of output devices. This is the high-power PA that the design evolution ends with after the incremental improvements have been added to the basic design. Truly, Ch.3 of the 1st ed (which seems toi be Ch.4 of the 2nd?) is probably the best demonstration of how to go from a very common and lack-luster circuit to one that has highly respectable performance, while explaining what each improvement does. Kidos to Bob !!
BC-1 is the same as Fig.3-13 in the 1sr edition, with all the "finesse" parts added (base-stops for output devices, better bias reg, etc). In the demo version the amp is the usual asymmetric input stage with current-mirror, feeding an EF-improved TIS, then an EF3 with 4-poairs of output devices. This is the high-power PA that the design evolution ends with after the incremental improvements have been added to the basic design. Truly, Ch.3 of the 1st ed (which seems toi be Ch.4 of the 2nd?) is probably the best demonstration of how to go from a very common and lack-luster circuit to one that has highly respectable performance, while explaining what each improvement does. Kidos to Bob !!
Yes it was. Additionally - it kept me off the streets!
With my transformer - which is an ancient IPL toriod. I got 174W/chan, both chan. driven into 8ohms. 264W/chan both chan driven into 4ohms. Single channel driven 4 ohms, 350W. Single, 8ohm, 200W. 120VAC power input controlled by variac.
I just got my E1DA Cosmos ADC today! Yeah! So distortion measurements will soon follow.
I designed and made pcbs of a low noise differential input circuit, inspired by Self. I can sell you a couple of blank pcbs if you're interested. BTL mode was realized by 'mis-wiring' one channel's input cable.
Hi Zoji,
Nice job !
I am looking at self's balanced input also but I will likely need to design my own pcb to suit the case and layout I am using....
Is that a zener dropper regulator from the main rail ?
-Dan
Nice job !
I am looking at self's balanced input also but I will likely need to design my own pcb to suit the case and layout I am using....
Is that a zener dropper regulator from the main rail ?
-Dan
Hi,
Finally got some time, when I looked at the ltspice .asc I noticed there is an .inc for Cordell models A. Those are not on his website nor included.
/örjan
Finally got some time, when I looked at the ltspice .asc I noticed there is an .inc for Cordell models A. Those are not on his website nor included.
/örjan
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In the AFE schematics/BOM R33 is 1k, in the book R20 is 2.2k ( different numbering ). I thought R29 and R33 ( AFE numbering ), should be of the same value, as they are in the book?
/örjan
/örjan
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Things change, book can't change, cast in stone. In my sim its R20. It was changed in a later revision to 1k, stronger pull down and we added a 470//100p in series with the base of Q8 as well.
Discovered while testing the AFE stand-alone, I could latch up the AFE with a huge overload signal. The sim will not show this behavior.
Discovered while testing the AFE stand-alone, I could latch up the AFE with a huge overload signal. The sim will not show this behavior.