The Other 13E1 SE-OTL

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Ray P
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#211 Re: The Other 13E1 SE-OTL

Post by Ray P »

I've spent some time with the 13E1 this morning'; source is my Buffalo3SE networked DAC being streamed PCM data from HQ Player (upsampled to 192KHz). It continues to make me smile, the sound is sweet and detailed with good weight. Imaging is superb, 3D like, similar to that with the 300B OTLs. The extra weight to the sound has really addressed what I perceived as a slightly lightweight sound with the 300Bs driving my Lowther horns and I'm starting to seriously question whether I need to build new speakers. I need to stress it a bit with some full-on, complex orchestral music to see how it stands up. It'll also be interesting to hear the comparison with the 6C33C build that is nearing first switch-on.

Anyway, I've now settled on a cathode sink current of 475mA (B+ is 160V so dissipation is 76W so around 20% inside the 13E1 max). Heat dissipation of the current sink mosfet seems fine at that setting, I'm measuring temperatures on the chassis, to which its mounted of upper 30s deg C.

I've left the feedback level alone for now as it sounds sweet but will try making some adjustments this coming week (I have a weeks leave so hope to have some good play time between getting the gardening and DIY chores done). As you can see from the pictures, I've now installed the base and feet so it's no longer balanced on various things and all that remains to be done other than exploring the feedback level, is to do the woodwork to make the front panel and design/make some sort of decorative collar to disguise the toroid cover mounting flanges/bolts - I'm thinking something from another piece of olive wood might look nice but I'm a little daunted by the complexity of the shape. Although the thing is hopelessly inefficient and will make a nice room heater in winter, the chassis only gets warm to the touch so I'm comfortable with having wooden panels.

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Image
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pre65
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#212 Re: The Other 13E1 SE-OTL

Post by pre65 »

Well done Ray, I'm glad that it is to your liking. :)
The only thing necessary for the triumph of evil is for good men to do nothing.

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Ray P
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#213 Re: The Other 13E1 SE-OTL

Post by Ray P »

pre65 wrote: Sat Jul 11, 2020 12:01 pm Well done Ray, I'm glad that it is to your liking. :)
Cheer's Phil. How's your MoFo this morning - I hope you getting as much pleasure from it.
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Ray P
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#214 Re: The Other 13E1 SE-OTL

Post by Ray P »

I'm just working on the finishing touches to this amp build so I can enjoy it without sitting there thinking 'I must finish that amp...'

I had a collar to tidy up the toroid covers 3D printed, one or two little flaws in the printing but overall I think it's a good job. Would have liked it in black but beggars can't be choosers!

Image

and I've been working on the olive wood front panel again, drilled it and have been applying Liberon finishing oil, with a rub down with very fine wire wool between coats - it's coming on nicely.

Image

Thanks to Ant for putting me on to repurposing a chopping board.
Last edited by Ray P on Sun Sep 20, 2020 4:15 pm, edited 3 times in total.
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#215 Re: The Other 13E1 SE-OTL

Post by Ant »

Its good stuff, trying to get the timber with that kind of grain pattern elsewhere is a right pain
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#216 Re: The Other 13E1 SE-OTL

Post by jack »

Ray P wrote: Sun Sep 20, 2020 3:54 pm ...Would have liked it in black but beggars can't be choosers!
Matt black spray? Stuff used for woodburners etc. should hold up well, but pretty much any decent quality spray should be fine.
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Ray P
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#217 Re: The Other 13E1 SE-OTL

Post by Ray P »

jack wrote: Sun Sep 20, 2020 7:45 pm Matt black spray? Stuff used for woodburners etc. should hold up well, but pretty much any decent quality spray should be fine.
I've already considered spray painting it but my experience with these sort of plastics isn't good.
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Greg
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#218 Re: The Other 13E1 SE-OTL

Post by Greg »

Ray P wrote: Sun Sep 20, 2020 7:51 pm
jack wrote: Sun Sep 20, 2020 7:45 pm Matt black spray? Stuff used for woodburners etc. should hold up well, but pretty much any decent quality spray should be fine.
I've already considered spray painting it but my experience with these sort of plastics isn't good.
Yes, you are right to be cautious on this one. What would work undoubtably is Humbrol oil based spray paint. Takes a little while to dry, but it doesn’t dissolve the surface it is fixing to and can look really good. I’ve used it in this sort of application many times.
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Ray P
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#219 Re: The Other 13E1 SE-OTL

Post by Ray P »

In a perfect scenario I would like to have made the toroid collars in Olive wood to match the front panel but the shape is complex (you should see the recessing underneath!) so it would have been an expensive CNC routing job.
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#220 Re: The Other 13E1 SE-OTL

Post by Greg »

Was my previous post helpful?
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Ray P
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#221 Re: The Other 13E1 SE-OTL

Post by Ray P »

Greg wrote: Sun Sep 20, 2020 9:23 pm Was my previous post helpful?
Possibly Greg, I'll give some spray paints a try on some scrap 3D printed parts.
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#222 Re: The Other 13E1 SE-OTL

Post by Greg »

Ray P wrote: Sun Sep 20, 2020 9:57 pm
Greg wrote: Sun Sep 20, 2020 9:23 pm Was my previous post helpful?
Possibly Greg, I'll give some spray paints a try on some scrap 3D printed parts.
Ok, realise, most spray paints have a cellulose base which will attack a plastic surface. Humbrol paints are oil based and do not attack a plastic surface at all. Of course, evaporation is slower so they take longer to dry, but they give a fine finish. To me, your Tx cover shroud looks good as it is, but if you want an alternative colour, Humbrol is the way to go, IMHO.
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#223 Re: The Other 13E1 SE-OTL

Post by Ray P »

The part was 3D printed in Graphite (SLS) and it seems there are various options available for applying a finish to such parts;

https://www.3dhubs.com/knowledge-base/p ... ted-parts/

That said, looking at it again this morning the part is blacker in the flesh than in the pictures so, after having a think about it, I've decided to leave it as it is.
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#224 Re: The Other 13E1 SE-OTL

Post by pre65 »

Ray P wrote: Mon Sep 21, 2020 8:23 am
That said, looking at it again this morning the part is blacker in the flesh than in the pictures so, after having a think about it, I've decided to leave it as it is.
A wise decision Ray.
The only thing necessary for the triumph of evil is for good men to do nothing.

Edmund Burke

G-Popz THE easy listening connoisseur. (Philip)
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Ray P
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#225 Re: The Other 13E1 SE-OTL

Post by Ray P »

Finally all done!

Image

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I know, I should pay more attention to getting horizontals horizontal!

BTW, the little black knob on the front isn't a volume control, it's a selector for different feedback resistors, which I'll experiment with later (I found having two multiturn potentiometers just to fiddly to experiment with, spent far to long getting them adjusted to similar values).
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