DIY Gates 5215

[Whoops]

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Very nice design,
what software do you use for the 3D drawing?

Thanks

 

[rock soderstrom]

Very nice design,
what software do you use for the 3D drawing?

Thanks

I use EasyEDA for PCB design. (The 3D visualization is an integrated part of it). It is quite good, easy to learn and pretty powerful. It is very open for existing component, footprint and 3d model libraries. It is a full range application for PCB design and production and you can operate it online or local. You can adjust it quite good to your needs. I use it only for my self etching projects but you can export production ready files (eg. Gerbers).

The best thing is, it is for free!

https://easyeda.com/

 

[Whoops]

I use EasyEDA for PCB design. (The 3D visualization is an integrated part of it). It is quite good, easy to learn and pretty powerful. It is very open for existing component, footprint and 3d model libraries. It is a full range application for PCB design and production and you can operate it online or local. You can adjust it quite good to your needs. I use it only for my self etching projects but you can export production ready files (eg. Gerbers).

The best thing is, it is for free!

https://easyeda.com/

Very nice,
so it serves the same purpose as Eagle or KiCAD?

I've used Eagle in the past, but I find it's interface quite old and not user friendly.
KiCAD is free also but it doesn't have an Auto-Router function...

Does EasyEDA has Auto-Router capability?
Can I import Eagle Libraries into it?

Thank you so much

 

[rock soderstrom]

Yes, EasyEDA has a similar feature set. I also had a quick look at EAGLE and KICAD, I think EAGLE is a class or two above EasyEDA but to be honest it doesn't matter to me as I don't even use EasyEDA to its full potential. Most of the stuff I do is pretty simple.

EasyEDA is much more modern and easier to handle. Not as old-fashioned as KICAD. This familiar, modern handling was one of the reasons why I went with EasyEDA. It is really easy to learn.

I have to admit, I don't use the schematic editor that much, I draw my layouts directly by hand in the PCB designer in EasyEDA, which actually works and is another plus for me and my way of working. Quick and dirty, you can get results very quickly.

That's why I don't use autorouting, but I think this function is also available in EasyEDA.

https://docs.easyeda.com/en/PCB/Route/index.html
Edit:

EasyEDA can import Kicad, Altium and EAGLE files. I do not know in detail how good the import function is. I had good results with DXF Files...

https://docs.easyeda.com/en/Import/Import-Eagle/index.html

 

[Whoops]

Thanks mate
It's great to know

 

[MidnightArrakis]

Disclaimer: I am not an experienced PCB designer, maybe one step ahead of you!
I don't use ground planes for tube circuits, I prefer ultra fat traces up to 3mm and solderpads for the big components with a diameter up to 4,5mm.

Here as an example a project of mine. A headphone amp called Schwarzwald, as an idea how I do it. There are certainly better PCB designers, I find the SilentArts PCBs for example very well designed.

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PS: the filaments were freely wired here for flexibility reasons. Regarding the part sizes: I always print out my layout on paper first and check if my parts fit before I go ahead. My designs are always one sided, because I am "self etcher"

What are the EasyEDA search terms used when searching for the vacuum-tube socket 3D models? As an example, when I did a search for a 12AX7, the 3D model that showed up included -- BOTH -- a tube socket -- AND -- a tube!!! I couldn't merely find -- ONLY -- a tube socket. How is that done in EasyEDA?

THANKS!!!

/

 

[rock soderstrom]

What are the EasyEDA search terms used when searching for the vacuum-tube socket 3D models? As an example, when I did a search for a 12AX7, the 3D model that showed up included -- BOTH -- a tube socket -- AND -- a tube!!! I couldn't merely find -- ONLY -- a tube socket. How is that done in EasyEDA?

THANKS!!!

/

The model I use is named Valve_Noval-B9A_Dongxin-GZC9-B_Socket, so the keywords a "valve" "socket" "B9a".

Basically, you can link any model (even external DXF files) to any footprint. In the modelmanger you have the possibility to adjust the position and size dimensions of the model. Very handy but unfortunately you can't modify the color, Render and texture properties. AKAIK this is only possible externally in a 3D program like Blender, 3dMAX or Maya.

PS: Sorry @RSRecords for derailing your thread!

 

[MidnightArrakis]

The model I use is named Valve_Noval-B9A_Dongxin-GZC9-B_Socket, so the keywords a "valve" "socket" "B9a".

Basically, you can link any model (even external DXF files) to any footprint. In the modelmanger you have the possibility to adjust the position and size dimensions of the model. Very handy but unfortunately you can't modify the color, Render and texture properties. AKAIK this is only possible externally in a 3D program like Blender, 3dMAX or Maya.

PS: Sorry @RSRecords for derailing your thread!

>> A BIG AND HEARTY "THANKS SO MUCH!!" << I really appreciate that very much!!! THANKS!!!

And.....somewhat along the same lines.....the different terminology for the same things that are used on both sides of the "pond" only continues to make life difficult for all involved. E.U. = Valve / U.S. = Tube E.U. = Metric / U.S. = Imperial E.U. = Potata(h) / U.S. = Potato{e) U.K. = Queen / U.S. = President

I am not so certain that you need to offer an apology, however, because I am the one who asked the original question. Besides, if our little "side-track" ends up helping others with their projects, who's to say my question and your response is a "side-track"?

In any case.....THANK YOU SO MUCH!!!

/

 

[RSRecords]

Ok pcbs arrived today. Everything looks good. Probably went a little over kill with 2watt resistors pretty much everywhere but I’ve seen that in some vintage gates stuff
My plan is to make the feedback currently R1 adjustable. I plan to experiment but any starting places? 10k pot with a 47k fixed or could I get away with something more drastic

edit: wait those values don’t make sense really. Maybe 50k pot and 30k fixed.

 

[emrr]

Probably went a little over kill with 2watt resistors pretty much everywhere but I’ve seen that in some vintage gates stuff

....because 2W carbon has lower noise than 1/2W for the same current, and keeps it over time more as the resistor absorbs humidity. Metal film? 1/2W.

 

[rock soderstrom]

My plan is to make the feedback currently R1 adjustable. I plan to experiment but any starting places? 10k pot with a 47k fixed or could I get away with something more drastic

edit: wait those values don’t make sense really. Maybe 50k pot and 30k fixed

Good idea. I would try 100k pot plus 25k fixed resistor. You will hear the biggest difference if you turn off the feedback completely.

I wonder about C4. Somehow this guy seems obsolete to me, since the tap for feedback is behind C3 with the same capacity. I think I understand this arrangement now. ;-)

 

[RSRecords]

....because 2W carbon has lower noise than 1/2W for the same current, and keeps it over time more as the resistor absorbs humidity. Metal film? 1/2W.

Went with carbon comp where I could and 1/2w metal film where I couldn't.

Good idea. I would try 100k pot plus 25k fixed resistor. You will hear the biggest difference if you turn off the feedback completely.

I wonder about C4. Somehow this guy seems obsolete to me, since the tap for feedback is behind C3 with the same capacity. I think I understand this arrangement now. ;-)

OK cool, I'll start there. I plan to use a 23 position switch I have laying around so maybe that last step will be no fdbk. Or very little.

 

[rock soderstrom]

cool, I'll start there. I plan to use a 23 position switch I have laying around so maybe that last step will be no fdbk. Or very little.

I think a 23 position switch is overkill. As I said, I would start with a potentiometer and see which values make sense for me. With my build it was a total of 4 switch positions. More, original, less and no negative feedback. Where the last switch position is the most important for me. Of course, the whole depends on the purpose and taste. Let your ears decide.

 

[rackmonkey]

Went with carbon comp where I could and 1/2w metal film where I couldn't.

This gets brought up every couple of years or so around here, but It probably doesn’t hurt to reinforce it now and then.

Even if you’re one of us who try to stick to original parts where it matters in vintage designs, there’s zero benefit and actually good reason to avoid using carbon comp resistors anywhere but at the tube plates in small signal applications. There has to be sufficient voltage across the resistor to generate second the harmonic distortion that justifies their use. Use them anywhere else, and you’re just adding drift over time and potentially added noise (depending on where else you use them) for no audible benefit.

(It’s different with large signals, as in guitar amps (which are so noisy that some additional noise doesn’t matter anyway from a purely sonic perspective), where output stage grids and the stage immediately before the phase inverter have enough voltage potential to justify their use.)

See attachment for more detail.

 

[emrr]

This gets brought up every couple of years or so around here, but It probably doesn’t hurt to reinforce it now and then.

Even if you’re one of us who try to stick to original parts where it matters in vintage designs, there’s zero benefit and actually good reason to avoid using carbon comp resistors anywhere but at the tube plates in small signal applications. There has to be sufficient voltage across the resistor to generate second the harmonic distortion that justifies their use. Use them anywhere else, and you’re just adding drift over time and potentially added noise (depending on where else you use them) for no audible benefit.

(It’s different with large signals, as in guitar amps (which are so noisy that some additional noise doesn’t matter anyway from a purely sonic perspective), where output stage grids and the stage immediately before the phase inverter have enough voltage potential to justify their use.)

See attachment for more detail.

Interesting doc, hadn't seen that one.

Personal opinion is I don't see the point, really. Even in a zero feedback situation I hardly distinguish between carbon or metal film plate and cathode resistors, though the metal film sure are quieter. I hear the transformer primarily, then the tube. For this reason my argument with old stuff is usually to leave all in-spec original carbon EXCEPT first stage plate and cathode.

Circling back, pretty much any quality old stuff has overrated carbon in there so....this effect isn't happening much and surely wouldn't in a new build.

An amp like this Gates is pretty high feedback, designed NOT to have distortion. Similar amps of this era I've rebuilt different ways have all sounded 'better/clearer' with new metal film, and didn't lose any real desirable character. They're generally '60's clean' no matter which, so the carbon isn't doing anything for them, at least not compared to just going to a different circuit type altogether.

The old premium RCA and Cinema Engineering gear was all built with precision wire wound, no carbon in any audio circuit positions.

All the above illustrates why there are so many different opinions about it.

 

[RSRecords]

Nice read. part of this project is to experiment with a simple circuit to see how the parts affect the tone. I'll load up one with metal film and take some measurements when I get it all sorted.

 

[rackmonkey]

context is everything. EMRR’s point is right. The carbon resistor guidance in the PDF above is going to apply to a BA-2A, a MILA or some guitar amps, but not so much to a 5215.

 

[RSRecords]

so..finally built this thing in a big ole steel chassis. sounds good, low noise no hum issues.

Frequency response is a little . how can I flatten this out potentially? Input transformer is an original gates and the output is an a25. Thinking output loading?

The REW graph below is with a -40dB attenuator. (7.5k x2 with a 150R shunt). Minimum feedback original feedback and max feedback settings.

 

[mjrippe]

I think it has a beautiful smile!

 

[RSRecords]

Any ideas as to what might be causing the smiley this response? As expected the 600r strapped across the OT didn't do much other than knock the level down. Here's a picture so people believe it exists.