new build choice, 2nd gen 50w

[dbeasley]

Sorry I misunderstood. I thought you were wanting to do half power 100w/50w.

Pentode/triode will do that sure - but IME Everytime I've wired one up like that Ive never like the way triode mode sounds - triode mode never seems to sound like "half power" as much as it makes the amp sound muddier and less defined. JM2C. Try it out and let us know how it sounds. I personally like switching fixed/cathode bias as you do get the inevitable power reduction by running cathode bias AND it tends to sound more defined and clear in the low end than triode mode.

If I recall correctly, triode mode on any given pentode tube needs a much higher signal level to drive them properly than when wired in pentode mode.

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[Mr. dB]

triode mode never seems to sound like "half power" as much as it makes the amp sound muddier and less defined.

I had a bandmate with a Boogie IIC+ with "Simul Class" and its half-power or "Class A" switch had the same result. It wasn't enough quieter to matter, it just seemed "weaker". It seemed like more of a sales gimmick than a useful feature to me.

[Mr. dB]

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DSC_1651.JPG

What are you using for your pilot light? And what are you using for co-ax?

[Mr. dB]

Does this look like a reasonable substitute for the unobtainable Calrad relay?

https://www.radioshack.com/products/12v ... dpdt-relay

https://www.radioshack.com/products/10a-relay-socket

[norburybrook]

DSC_1652.JPG
DSC_1651.JPG

What are you using for your pilot light? And what are you using for co-ax?

Pilot light is this:

262771977572. eBay number

the coax is standard RG59 75ohm coax. Available easily.

M

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[Mr. dB]

Pilot light is this:

262771977572. eBay number

the coax is standard RG59 75ohm coax. Available easily.

Thanks. 220V is not for those of us on this side of the Atlantic, but here's something somewhat equivalent for Yanks?

https://www.ebay.com/itm/3pcs-110V-AC-D ... Swa2ZakEop

[martin manning]

Marcus, do you have the FET relay thing worked out? I did some doodling on that for possible application to my ODS, updated below [see in files section]. You may not need to shield all the signal runs if they are short. Most critical are the FET input and the V1 grid.

[norburybrook]

Martin,

I'm waiting for my pot to arrive. It's easter here so everything postal wise is on hold!

I think everything is as it should be wiring wise I don't have any 9v batteries spare to check the exact voltages.

My FET board is about 6 inches from the pot /Guitar input.

I have some very thin Van Damme multicore that is shielded and I was going to use that as it's balanced so 3 conductors, one for each leg.

I found a layout somewhere with the wiring for this on a the relays. I need to find it again.

I'll post the relevant part .

m

[norburybrook]

Found it.

2nd Gen Hybrid-FET realys.jpg

M

[martin manning]

I don’t like it. The 1M needs to stay on the V1 grid. Compare my schematic.

[erwin_ve]

I don’t like it. The 1M needs to stay on the V1 grid. Compare my schematic.

Is that because it messes with the 3M3 resistor on the Fet board?

[martin manning]

Yes, correct. That’s the way it works with the switching jacks.

[norburybrook]

OK.

Can you have a look at this and work out the new wiring for the of OD relay and the send return? The orange lines are what I think it should be for the send return.

I have only one master so it's a little confusing, along with no return and a weird relay.

70's hybrid relays.jpg

thanks

marcus

[norburybrook]

Transformers and choke installed. Wired up the whole power section, voltage regulator etc etc . Fitted relay boards,need some help with the relays. Hopefully my pot and 5pin foot switch socket will arrive tomorrow and can crack on.

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[erwin_ve]

OK.

Can you have a look at this and work out the new wiring for the of OD relay and the send return? The orange lines are what I think it should be for the send return.

I have only one master so it's a little confusing, along with no return and a weird relay.

70's hybrid relays.jpg

thanks

marcus

Marcus, the send return is OK.
You can do the relay wiring I'm sure. Do you know what pins are doing what on the relay?