dynaco?

[selloutrr]

which wrecks used dynaco iron? .... if any...

[dartanion]

Rocket used the Dynaco A470 OT.

[selloutrr]

ok, I learned something new today.

which PT was originally used with the rocket?

[dartanion]

ok, I learned something new today.

which PT was originally used with the rocket?

Not sure, but I would wager it was a Stancor like what was used in the Express and Liverpool. There were so few Rockets made that info is fairly sparse. I am sure Allyn can fill us in on the PT details.

[Structo]

That is kind of strange.
For some reason I figured the Rocket was probably the most popular amp due to it being a bit more friendly.

Didn't Ken like the Rocket the best?

[dartanion]

The list of known wrecks that was posted in various threads only shows 6 Rockets. I have heard that the actual number was in the teens, but I haven't seen them all documented. The ones on the list show mostly new Heyboer PTs, which would be the Stancor clone PT.

[selloutrr]

I can't find the stancor model number for the PT.

[M Fowler]

I don't know can't seen to find that info.

Here is the Stancor transformer catalog.

http://www.bunkerofdoom.com/xfm/index.html

[Cliff Schecht]

I don't think Stancor made an OT that Ken would have used in the Rocket. The two that come to mind are the A-3800 and the A3851. The first one is much more likely as it is physically bigger and doesn't have the goofy 10% inverse feedback windings the 3851 has. The A-3800 is a 5kOhms @ 80mA primary and the 3851 is 4.4kOhm @ 70 mA. While the 3851 impedance might seem more appropriate for a Rocket, I have always preferred the A-3800 with a quad of 84's and think it fits the Rocket sound well.

But as I said, I don't think Ken used these at all, there are better options out there like the Dynaco A470 iron he was (I think) known to use. That's a transformer with great sonic properties. They use a special winding method that helps maintain inductance and balance under heavy loading for low distortion and great frequency response. I wish I had one to try with a Rocket but I've never been able to find one for cheap. Anybody tried the Triode Store A470 clones?

I think the power transformer is much less critical. I bought a cheap Stancor transformer (P-8172) from Dynaman and thought it worked great in my Rocket build. Only problem was the transformer didn't have mounting hardware so I had to fabricate some. Also it's wound for 117V so you really gotta step down the wall voltage to get the voltages right. Again probably not what Ken used.

Do we have any public pics of Rocket guts yet? You Rocket owners afraid of ruining the value of your amps?

[selloutrr]

I have a feeling the PT is from a later date catalog. Nothing in those data sheets match exactly what the current iron is based on.

[talbany]

..I've used the real Dynaco A40's in several builds (mostly 34's Express) and are no doubt KILLER!! iron but IMHO the 470 is WAY overkill for any 4 el84 amp (even Ken's) and I love BIG iron..Although they were designed for a pair of 34's or 6550/88's these transformers were 100% over spec and can easily handle 100 watts on a bad day.. forget about even coming close to core saturation on these transformers with a Liverpool or Rocket..
A 470 weight pushing 10lbs


Tony

[M Fowler]

I've used the Triode dynaclone A-470-S on several builds and it is a great transformer.

In what Tony was referring to as this OT being over kill for the four EL84 I was wondering that myself as the specs on this OT shows 35/70w.

Triode notes this: This type of transformer can be used with many tube types, such as 6550, KT88, KT90, 6CA7/EL34, 300B, 2A3, 6B4 or push-pull parallel 6BQ5/EL84 & 6V6-GT. It may be used with triode, pentode, or ultralinear (screen tap connection) wired tube arrangements.

I don't think Ken was using a Stancor PT on the Rocket amp based on review of the Stancor catalogs and past posts on TAG. All posted indicated the use of 3801 or 3800 OT on liverpool and Express but nothing much confirmed regarding Rocket iron.

Mark

[dartanion]

The Triode A470 OTs are made by Heyboer. The A470-S I believe was Chris' (Toneslut) OT that he had Heyboer make.

On the PT, I am not sure at all what Ken used, but the 5199 or the Pacific work great for Rockets.

[M Fowler]

No Triode sells the A-470-S and the Heyboer copy is different I have run both OTs.

http://triodestore.com/noname.html

Mark

[dartanion]

My bad. I know there are 4 different version of the A470 that Chris had made, one may be exactly like the one Triode sells.

I just started using the Pacific Rocket OTs, which are very nice.