New spin for ST-35 Design

Hello Tube lovers, Some may know me. I'm a ST-35 lover, the sound, then simplicity and the design.
I rebuilt the Dynaco St-35.
It uses ½ 12AX7A and ½ a 12AU7 per channel. The 12AX7A is a low noise preamplifier that directly drives the cathodes phase splitter 12AU7. I also replaced a single cathode resistor and capacitor with four individual resistors and capacitors. The original cathode bias resistor has been replaced with individual feature that allows your ST-35 to perform to its full potential. The circuit incorporates 4 trim pots to set individual Bias per EL-84. Once adjusted with 0.35V, the amplifier is ready to operate. For best performance is recommended to have a well quad matched EL-84 tube on this project.

Open to conversation.

Here it's my assembly:

Are you selling those?

Is that more-or-less a copy of a Shannon Parks / DIYTube board?

alanhuth wrote:Are you selling those?

Yes I'm you can start with bare PCB or populated PCB. Soon I'm putting for sale the chassis with plates back again.
I run out of enclosures. We are placing order for the enclosures.

You can find me on ebay.

https://www.ebay.com/itm/225447461751?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=wzZzolA2RqW&sssrc=2524149&ssuid=wzZzolA2RqW&widget_ver=artemis&media=COPY

or here:

https://www.ebay.com/itm/225066317444?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=wzZzolA2RqW&sssrc=2524149&ssuid=wzZzolA2RqW&widget_ver=artemis&media=COPY

Donkeyshins wrote:Is that more-or-less a copy of a Shannon Parks / DIYTube board?

Correct, in fact I chat with Shannon about it. It's similar design. It fits with his board.

I'm intrigued. I have never heard an ST-35 but some people I respect say it's a wonderful amp. One guy on YT traded in his Alan Eaton 45 SET for a Kenny Russell version, saying it sounded even better, which is a very high bar, IMHO. I have two Alan Eaton 45's myself.

Question: how do I know that a new, "upgraded" version of the ST-35 has the magic of the original, particularly if it has different parts, including the transformers, which many people say are the heart of the amplifier?

Can you point me to any credible, authoritative voices who have heard your version of the ST-35 and agree that it sounds at least as good as the original, despite the changes you made?

Thanks. It sounds a little hostile the way I said that, and I apologize. Not intended. But if I am going to put out the money and effort, I'd like some confidence about what i'm getting into. I know you have been around here for a while, but I'm kind of a newbie, so please forgive my ignorance.

Alan

alanhuth wrote:I'm intrigued.  I have never heard an ST-35 but some people I respect say it's a wonderful amp.  One guy on YT traded in his Alan Eaton 45 SET for a Kenny Russell version, saying it sounded even better, which is a very high bar, IMHO.  I have two Alan Eaton 45's myself.  

Question: how do I know that a new, "upgraded" version of the ST-35 has the magic of the original, particularly if it has different parts, including the transformers, which many people say are the heart of the amplifier?  

Can you point me to any credible, authoritative voices who have heard your version of the ST-35 and agree that it sounds at least as good as the original, despite the changes you made?

Thanks. It sounds a little hostile the way I said that, and I apologize.  Not intended.  But if I am going to put out the money and effort, I'd like some confidence about what i'm getting into.  I know you have been around here for a while, but I'm kind of a newbie, so please forgive my ignorance.  

Alan

Hello Alan,

The new design with ST-35 is similar to the Triode ST-35 sold long ago, and Shannon Board, as I mentioned.
You certainly can research for several feedbacks and authoritative voices about this design.
I'll point to you some of them here:

https://triodeaudio.blogspot.com/2008/02/diytube-dynaco-st-35.html

You can find more information about this circuit here from triode as well.

https://store.triodestore.com/diy35kit.htmlhttps://store.triodestore.com/diy35kit.html

Also, on Shannon's forum that nowadays is mostly obsolete.

http://www.diytube.com/phpBB2/viewtopic.php?f=1&t=6071&p=49742#p49742

Rev E PCB is 100% fitting with HALG PCB.

you can also research on Facebook about HALG board and feedback.

You'll see and observe that the EL-84 with this new design has a magic sound. You can use any transformer: Dyna kit, ADCOR, HAMMOND, Triode.
Manual of this board is composed of 24 pages for assembly. BOM, schematic, mechanics, block diagram are also provided on the kit. A complete excel sheet of parts is provided.

Let me know if you need more info.

Hi OldTube,

Thanks so much for your quick and thorough reply. I’ll go through your links. I must say I’m surprised that you say you can use any transformer. I can’t tell you how many times I’ve seen people say the Dynaco transformers are the secret sauce.

Also, you mentioned that you plan to release chassis for this. Do you have any update on that?

Thanks,

Alan

Hello Alan,

I should have enclosure for it in 2 weeks.
I have to confirm for which transformer I have the top plates, since they differed in size, and I have usually for Dyna kit and EDCOR.
They are built in my partner wood shop. They are hand made with high quality wood.

Keep in touch!

Looking forward to it.

I'm still curious about the transformers. You don't seem to agree with the conventional view that the Dynaco transformers, in particular, are a big part of the secret sauce(?)

Hello Alan,

The Dynaco transformer, sold as replica Dynakit (the PA-774 and Z-565) today has a slightly better response in frequency and less distortion than EDCOR and HAMMOND.
But that doesn't mean the EDCOR and HAMMOND have bad musicality. The 3 transformers are really good. You can find several blogs comparing them.
If you want to get a very close response, I'd suggest to get the Dyankit.

I personally like the EDCORs better, but this is myself.
There's another option as well to use ANTEK (toroidal), but for this I don't have plate design yet.

Is up to you there.

Hi Oldtube,

Any update on the enclosure? I will want to get one for dyna transformers.

Alan

Hello Alan,

This weekend I finally heard back from the wood shop.
The enclosure should be ready this Sunday for me, 3/26, finally.

He had some of his machine tools down and got delayed.

I should have this ready on next week online.

I'll post pics here as well.

Cheers

Hello Alan, and all,

After extensive weeks of overloaded work, I was able to bring 2 more samples of the HALG Chassis to life.
I'll detail the type of wood and all characteristics here later.
The wood is basically ready, just missing the finishing.
The top plates for Dynaco are the one's I'm working with my friend Mechanical shop.
Here are some insights of what is coming.

The wood guy takes a lot of pride of his magnific work!




Give me just this week and i should have this ready for sale.

Thanks!!

Hello Gang!

As you can see the wood shop is owned by 27 years of crafting and designing products with wood.

This will compose 1 enclosure kit:

Wood Chassis Size: 13W x 10D x 3H inches

Wood Detail
Fabricate (2) frames Heavy duty construction hand selected quarter sawn white ash. Both units from single boards.
Chassis is 0.778 inches thick (19.8 mm). Rebated for top and bottom plates. Mitre joints reinforced with biscuits and corner blocks. Designed to handle heavy components.
Drilled for inserts, drill and routed for rear access panel, chamfered edges.
Sanded to 150 grit and finished with bee wax.

Top Plate
Top panel available in a choice of Polished Multipurpose 6061 Aluminum Sheet or Stailess Still like mirror.
Top chassis is thick enough to support heavy transformers without bowing.
0.08” (2 mm) thick
Top plate comes with option of Dynaco or Edcor transformers
Top plate also accommodates 1 main switch cut out
Ready cut outs for HALG ST-35 board

Bottom plate
Designed with cut outs to proper ventilate the amplifier.
Polished Multipurpose 6061 Aluminum Sheet
0.08” (2 mm) thick
Includes four large round rubber feet (0.75” dia. x 0.56” high) with mounting hardware into
inserts to avoid wood damage.

Back plate
Designed with cut outs to accommodate RCA inputs, banana outputs, Potentiometer (Vol), 110/220V switch, main input AC filter.
Polished Multipurpose 6061 Aluminum Sheet
0.08” (2 mm) thick

Screws:
8 x 316 Stainless Steel Button Head Hex Drive Screw, Super-Corrosion-Resistant, 8-32 Thread Size, 7/16" Long

Hello guys!

Here is the link!

https://www.ebay.com/itm/225516436529?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=wzZzolA2RqW&sssrc=2524149&ssuid=wzZzolA2RqW&widget_ver=artemis&media=COPY

Enjoy!

Nice. It looks like the one for sale is for Edcor transformers. How can I know when you have one ready for Dynaco?

Sorry for delay in replying. I used to get notifications if somebody posted in a thread I posted in but that doesn’t seem to be happening any more.

Hi Oldtube,

Also, do your instructions and/or BOMs include suggestions for upgrade options for capacitors, resistors, etc?

Thanks

alanhuth wrote:Nice.  It looks like the one for sale is for Edcor transformers.  How can I know when you have one ready for Dynaco?

Sorry for delay in replying.  I used to get notifications if somebody posted in a thread I posted in but that doesn’t seem to be happening any more.  

Yes, I'm just waiting for my quote to come. By tomorrow I should have it, and I should get 10 New Top Dynaco Plates.
I'll open a new page on ebay for Dynaco.

alanhuth wrote:Hi Oldtube,

Also, do your instructions and/or BOMs include suggestions for upgrade options for capacitors, resistors, etc?

Thanks

The Manual is 24 pages with all detail and instructions on which components, transformers, and hardware to buy. It gives Block diagram of connections, board top view assembly, schematic and how to power the amp, voltages currents, and how to adjust the amp.

You should be all good with all instructions.

I notice that Kenny Russell offers lots of upgrade options for his builds.   I assume that these upgrades have some value, some probably more than others.  What would be ideal would be some notion of which ones provide the most bang for the buck and which ones can be passed without missing anything.  I’m. hoping that your instructions offer some recommendations on that.  Obviously, your populated board cannot have most of these “upgrades” just based on price. But it may be worthwhile making a few strategic changes. I’m just wondering. Here are his upgrades:

Resistor upgrade 1 (standard carbon film and carbon composition) - $40
Resistor upgrade 2 (high end metal film) $40
Resistor upgrade 3 (Takman carbon and metal film mix) $60
Resistor upgrade 4 (carbon comp and Takman metal film mix) $50
Capacitor upgrade 1 (Vcap ODAM) $200
Capacitor upgrade 2 (Mundorf MCap ZN Series) $75

https://getdynaco.com/collections/st-35-resistor-upgrades
https://getdynaco.com/collections/st-35-amplifier-options?filter.v.price.gte=&filter.v.price.lte=&filter.p.product_type=Capacitors+ST-35&sort_by=manual

alanhuth wrote:I notice that Kenny Russell offers lots of upgrade options for his builds.   I assume that these upgrades have some value, some probably more than others.  What would be ideal would be some notion of which ones provide the most bang for the buck and which ones can be passed without missing anything.  I’m. hoping that your instructions offer some recommendations on that.  Obviously, your populated board cannot have most of these “upgrades” just based on price.  But it may be worthwhile making a few strategic changes.  I’m just wondering.  Here are his upgrades:

Resistor upgrade 1 (standard carbon film and carbon composition) - $40
Resistor upgrade 2 (high end metal film) $40
Resistor upgrade 3 (Takman carbon and metal film mix) $60
Resistor upgrade 4 (carbon comp and Takman metal film mix) $50
Capacitor upgrade 1 (Vcap ODAM) $200
Capacitor upgrade 2 (Mundorf MCap ZN Series) $75

https://getdynaco.com/collections/st-35-resistor-upgrades
https://getdynaco.com/collections/st-35-amplifier-options?filter.v.price.gte=&filter.v.price.lte=&filter.p.product_type=Capacitors+ST-35&sort_by=manual

All here is valid! Certainly, I do not have all of those on mine, but I do have good parts there. You can see by the pictures.
Those updates are not mentioned on my BOM. It is left open for you to decide.
All flavors for all pockets, right?!

Capacitors are valid, and I'd say mostly the ones on the audio path, like Copling caps.

I would not expend any extra until you listen the result! You will be surprised!

Hello,

Dynaco Plates in house! Ready for sale on Ebay.

https://www.ebay.com/itm/225529291601?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=wzZzolA2RqW&sssrc=2524149&ssuid=wzZzolA2RqW&widget_ver=artemis&media=COPY

Thanks!

I intend to buy this setup. Small financial re-prioritization, so it may take a while, but my heart is in the right place. I hope this is still available when the money is.

You are welcome!

Thanks!