diytube.com

I just wanted to introduce myself as I am new to the forum. I am a long time audiophile mostly into SS stuff like McIntosh and early Marantz. However I recently acquired a Dynaco Mark IV in very nice shape that I plan on restoring and possibly adding the Posiedon board. Will the Poseidon Board be a direct drop-in or are the dimensions different? I believe the Mark III's have a different size PCB board than the IV's which is why I'm asking.

Are there many Mark IV owners here? They don't seem to be as popular as the other amps. Are they much rarer? It looks like its going to be tough to find a vintage matching amp to complete a pair as most of the ads everywhere are for the ST-70, ST-35 or Mark III.

This tube stuff is really addicting (and fascinating) as I find myself slowly crossing over...

Greg

Welcome aboard!

I wouldn't say a Mark-IV wasn't as popular... you just have to compare them to other monoblocks and there the popularity shines :-)

Cheers!

Geek wrote:Welcome aboard!

I wouldn't say a Mark-IV wasn't as popular... you just have to compare them to other monoblocks and there the popularity shines :-)

Cheers!

Thanks Gregg.

I would image the sound signature is similar to the Mark III only with slightly less power. In regards to the other comparisons, was that just a general statement as to the SQ? I taking this to mean the Mark IV holds its own against other monos.

Welcome Greg!

The MK-IV board is physically the same size as the MK-III,
and the Poseidon will work fine. See the manual which
is in the first post in the forum for details. There are two
sets of parts lists and schematics in the manual, as the
parts values are somewhat different.

If you decide to convert, may I suggest you might want to
think about building (and testing) two identical Poseidon
boards now, so when that elusive second amp shows up
on eBay and you snag it, you'll have a pre-built Poseison
ready to go. The other reason to do it now, is that the
boards will have matched parts, which may not happen if
you do it down the road. Just a thought.

... tom

TomMcNally wrote:Welcome Greg!

The MK-IV board is physically the same size as the MK-III,
and the Poseidon will work fine. See the manual which
is in the first post in the forum for details. There are two
sets of parts lists and schematics in the manual, as the
parts values are somewhat different.

If you decide to convert, may I suggest you might want to
think about building (and testing) two identical Poseidon
boards now, so when that elusive second amp shows up
on eBay and you snag it, you'll have a pre-built Poseison
ready to go. The other reason to do it now, is that the
boards will have matched parts, which may not happen if
you do it down the road. Just a thought.

... tom

Thanks Tom.

That's good to know. The only reason I ask is because when I was looking at the Triode Electronics PCB's and they claim they downsized the Mark IV board to fit better but the circuit is identical to the Mark III. That suggests that there is a fitment difference. My other question would be why would TE make them smaller? Conversely the component layout must be tighter on the Posiedon board to accommodate both amps. In other words the components have more clearance from the chassis then on the Mark IV.

Greg

Well - our man Shannon - the designer and brains behind the
diytube boards - is clever. He made the Poseidon board a
little bit smaller, with holes that are right at the edges for
the MK-III, and on the sides for the MK-IV. I'm holding a
blank board in my hand right now. The board is 4 3/8 x 3 1/4
with holes 9/16 from each side on the short side, and in about
3/16" ...

Sorry if I gave away the secret Shannon!

haha

... tom

I vaguely remember working with a MKIV owner who sent me detailed measurements, photos and emails. That was a great help!

Shannon