Which A470 and why?

[VintageCharlie]

Hi guys!

I'm beginning my way towards an AC30/Trainwreck Rocket, which might see various experimentations in different directions after i build a stock circuit.
I'm leaning towards the Rocket after i heard the comparison clips between an ac30 clone and a rocket clone in a thread over here (due to the additional transparency and detail i hear in the rocket clips, which is what i strive for). The poster said that the Toneslut OT was used, which i assume to be another type of clone from the A470?

I read as many A470 related threads as i could, but i only get more and more confused. From what i gather, there are many clones available - dynaclone from triode, Heyboer from RJ, then there's the Moose and Allen being mentioned (i don't know where to find these or order them?) and thern some others i've probably forgotten right now.
Then there's some talk about how the Heyboer version differs from the original - supposedly it includes a mod that KF ordered from Dynace - the OT is wound with 7 instead of 5 strings or something (sorry, no clue what this is about). Then i read the Heyboer has M19 instead of M6 steel laminations, in order to make it less hi-fi'ish. I don't know what steel the others use - for instance the dynaclone from triode.
After reading all this, i have no idea which would be the closest to the legendary A470?
Also would an original A470 from the 60's be a better choice - even if it's a bit rusty, has shorter leads that probably have to be extended? Also is this "Ken Fisher mod" to the A470 that supposedly was incorporated into his OT's of any significance? If so, would the Heyboer from RJ or the Dynaclone be a better chocie than an original, or shoudl the original be hands down the best choice?

If talking about originals - how were the old 60's dynacos - were they consistent in quality - was it a hi-end or a budget item at that time?

I'm leaning towards an Original, but i just want to check with you guys and see what the more experienced brains tell you.

Oh, one last thing - i was also considering an AC30 style OT, but i'm wondering if there would be a way to roll off the lower bass frequencies in the amp to approximate the response of an AC30 OT, in case i don't like the additional bass reserves from the A470? (maybe like Orange does it with variable caps selector?)

I'd really appreciate any input on this, as i'm a bit lost...
Thank you very much in advance!

Kind regards,

VintageCharlie

[VintageCharlie]

Forgot to ask if and how the original Dynaco A470's differ between various production dates - are the 60's ones identical to the 70's, 80's - spec and quality wise?

Btw. to me it seems like a 4k primary on the OT is probably the most versatile impedance - AC30's, 50w Marshalls, 50w Fenders share an identical or very close impedance to that - hence due to its broad bandwidth it should be a very versatyle OT for various builds (ok, it might not give spot-on Marshall or Fender tones, but good approximations of those with some extra detail in frequencies that are drown in those amps by their respective OT's (at least this is how i imagine it).
At the moment i also have a 3.5k Drake clone, which comes close impedance-wise, but that one probably can't touch the amount of detail the Dynaco types can put out.

[billyz]

The A470 is an Ultra linear design . I would bet that KF's mod was to stuff the unused tap inside the end covers. That's what I do with them. Insulated of course.

[LeftyStrat]

I haven't tried any of the others, but I have an A470 from Triode.

I also have an original Dynaco A470, cloth insulation and all, and I compared the two in several circuits and they are sonically and visually identical. Except of course for the cloth insulation.

Occasionally you can find originals on eBay, but honestly, I wouldn't spend any more than what I could get the Triode version for.

[LeftyStrat]

Forgot to add, this is a great transformer, and you're right, they can serve as a great OT for a lot of different amps. I'm even planning on using one for a Dumble with a quad of 6v6's.

[selloutrr]

I haven't tried any of the others, but I have an A470 from Triode.

I also have an original Dynaco A470, cloth insulation and all, and I compared the two in several circuits and they are sonically and visually identical. Except of course for the cloth insulation.

Occasionally you can find originals on eBay, but honestly, I wouldn't spend any more than what I could get the Triode version for.

Triad and Dynaco A470 are identical Triode out sourced most of the production.

The correct Model number for TW:
DYNACO A-470-s

[selloutrr]

The A470 is an Ultra linear design . I would bet that KF's mod was to stuff the unused tap inside the end covers. That's what I do with them. Insulated of course.

From what I've researched. The Dynaco A470 transformers were worked on/rewound by Merren before being used in TW Rocket.

[LeftyStrat]

Triad and Dynaco A470 are identical Triode out sourced most of the production.

The correct Model number for TW:
DYNACO A-470-s

So can we get these for less than what Triode sells them for? Love to find a cheaper source.

[M Fowler]

I also like rjguitars Edcor A470-S version very good sounding OT.

Mark

[LeftyStrat]

I also like rjguitars Edcor A470-S version very good sounding OT.

Mark

What do these sell for?

And hey, aren't you supposed to be resting?

[VintageCharlie]

Thanks for the many replies people!
The picture looks a bit clearer to me now.

I'm leaning towards the Triode Dynaclone vs Heyboer from RJ.
As the amp will probably see some attenuator use and will be hooked up to a resistive load quite a bit, an original OT might not be a good idea with the extra punishment it's going to see.

Has somebody compared the RJ Heyboer version to the Dynaclone from Triode in the same amp?

I'm not sure what i should go for - one that has the m6 (dynaclone) or the m19 (heyboer) steel laminations?

So is the Heyboer HTS 8093-1 available from RJ also the one that that incorporates the mod that KF preferred for this OT?
What exactly would the m19 vs m6 result in that OT? I read that the m19 would give more harmonics and be "richer" (more complex and distorted?)?

OT's are such a tricky thing to decide on as hardly anyone has ever compared different OT's of the same type in the same exact amp

[FUCHSAUDIO]

The A470 is an Ultra linear design . I would bet that KF's mod was to stuff the unused tap inside the end covers. That's what I do with them. Insulated of course.

From what I've researched. The Dynaco A470 transformers were worked on/rewound by Merren before being used in TW Rocket.

Sounds a little hard to swallow honestly...what could he possibly have done ?

[2tone]

I never heard ken talk about Merren reworking any dynaco OT. I don't think Ken actually used an original dynaco in any Rocket...

[VintageCharlie]

This is a great forum with loads of very useful and detailed info, but the transformer aspect of Trainwrecks seems to be connected to many different opinions - i guess probably because there was a lot of variation and it is hard to know for sure what exactly was going on.
I guess it would be rather interesting to hear first hand experiences in regard to the comparison between the various A470 clones and types available, as i'd like to get one that fits my aims.
I'd be interested in an OT that is as versatile as possible - with the broad bandwidth these are known for, but without sounding too clean/sterile or shrill. I'm not after any hi-fi'ish tone, i hope to get a really detailed, transparent, but in the same time rich and harmonically complex tone (not necessarily "uncoloured") that is not harsh or peircing in the highs despite the wide high frequency response - i have no clue if the Dynaclone or the Heyboer with the m19 lams or one of the other options would be best for this purpose - that's my main concern. I've no idea what Ken mostly used and most threads on this that i have found don't seem to lead to a consensus.
I'm just interested in the A470 specifically because of the many positive reviews it gets here - just don't know which would fit my needs best.
(a buddy is traveling from US back to Latvia and he can take it with him for me - no 50$ shipping) - i'd be hesitant to order another one just to compare them side by side after this opportunity.

[redshark]

I like the pacific version of the A470-S. Sounds amazing in the rocket!!