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HI All,
Ordered my board yesterday! Still ordering other parts... So I have some a question as I study the schematics:

If I only use 4 and 8 ohm (Edcor) OT taps do I just connect the 16 ohm tap back to the junction block? Sorry never built anything with feedback loop.

It appears that the design uses 12.6 volt heaters- that a new one for me also - but that looks pretty straight forward.

Thanks!

You can tie the 16 ohm transformer lead to the feedback terminal strip directly. Just be sure the common transformer lead goes to ground. Simple. Not sure what you mean about12 volt filaments? The power transformer has two 6 volt windings that go in parallel.

See the green/brown and whites twisted ... that's how it hooks up. They need to be "in phase" ... that's easily figured out.

Thanks TOM.
OK-on edcor OT and I am not using the 16 tap for speakers-I am running 16 ohm green wire to J3.3 and J4.3 and feedback loop works fine regardless of not using 16 ohm output? OT commons goes to black/neg speaker jack and then to J2.3 and J5.3 to complete feedback loop...it doesn't have a leg going to chassis ground directly-correct?
Ok-no 12.6 heaters. I was confused by the two 6.3 heater taps instead of one- we are doing this to use a "off the shelf" transformer and we need greater amp rating than one single offers? Just trying to understand the architecture of the plan-I appreciate the help. Regarding the 16 ohm outputs are you seeing a demand from your HIFI customers on this or is this just an old dynaco hold over by using the old iron design? Thanks for the advice!

MacL wrote:OK-on edcor OT and I am not using the 16 tap for speakers-I am running 16 ohm green wire to J3.3 and J4.3 and feedback loop works fine regardless of not using 16 ohm output?

Correct.

MacL wrote: OT commons goes to black/neg speaker jack and then to J2.3 and J5.3 to complete feedback loop...it doesn't have a leg going to chassis ground directly-correct?

A wire will run from J1-6 to the chassis for ground reference. Otherwise your audio ground is on the PCB and its path is controlled.

MacL wrote:Ok-no 12.6 heaters. I was confused by the two 6.3 heater taps instead of one- we are doing this to use a "off the shelf" transformer and we need greater amp rating than one single offers? Just trying to understand the architecture of the plan-I appreciate the help. Regarding the 16 ohm outputs are you seeing a demand from your HIFI customers on this or is this just an old dynaco hold over by using the old iron design? Thanks for the advice!

Yes, this project was originally based on using the Dynaco SCA35 transformers and Triode Electronics then started making the same transformers (but the Z565s were with 4 & 8 ohm). 16 ohm transformers aren't necessary (per the manual). A single 6.3VAC secondary will work just fine if it is rated high enough, too.

Shannon