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Merlin Iron connection [message #31572] Tue, 06 December 2005 17:36 Go to next message
PakProtector is currently offline  PakProtector
Messages: 935
Registered: May 2009
Illuminati (2nd Degree)
hey-Hey!!!,
Heyboer is nearly ready to ship the modified version of the S265Q I arranged for the group buy.

Primary side connections from one anode to the other:
Grey---anode1
Blue---a1-40%
White---a1-30%
Black---a1-20%
Red---center tap
Black-Red stripe---a2-20%
White-Black stripe---a2-30%
Blue-Yellow stripe---a2-40%
Purple---anode2

Secondary takes output from the green and green/yellow for 8 and 16R. For 8 connect/strap the yellow and yellow/black and for 16 connect the black and black/white stripe. For 4R we put the two halves of the 16R winding in parallel.

I will post a schematic to projects as soon as I can visit a scanner.

Several inquiries made regarding the grid chokes. The Heyboer PN is HTS-7457. Specify a .002" gap of Nomex paper. Even though there is no DC, the gap is useful.

With this 10kOhm a-a OPTx, if you want to run an AB1 bias, draw the load line at ~2k5 as you would for SE, with a single set of plate curves. If you're staying Class A, draw the load line at 5k. Any of the three pairs of taps can be used for g2 connections. The E-Linear tap does noy have to be the same pair. Of course, class A U-L curves are not generally available...:(

Looking forward to seeing a few of these amps come together.
cheers,
Douglas



Re: Merlin Iron connection [message #31580 is a reply to message #31572] Wed, 07 December 2005 13:35 Go to previous messageGo to next message
Manualblock is currently offline  Manualblock
Messages: 4973
Registered: May 2009
Illuminati (13th Degree)
Say Doug; wasn't there a schematic posted earlier regarding this amp?

Re: Merlin Iron connection [message #31581 is a reply to message #31580] Wed, 07 December 2005 14:02 Go to previous message
PakProtector is currently offline  PakProtector
Messages: 935
Registered: May 2009
Illuminati (2nd Degree)
It is in the projects folder. No colour codes on that one. I also left out one of the E-Linear taps.

When I get through with the PCB design, I will revisit Merlin, and include notes as to which tag number the various connections go. Both CCS, and the upper elements of the cascode will go on the PCB, probably along with the plate loads for teh input stage. I wanted something approachable, and Melin is not that...:(
cheers,
Douglas

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