Page 8 of 11

#106 Re: Tweeter Amp for OB or Horns

Posted: Mon Jan 14, 2019 8:06 pm
by IslandPink
Yes but you've not got a fixed box size :confused3: This 'neat' business is doing my head in. There's still one too many parts for this volume. I'm trying to avoid getting the input phonos too near any toroids, getting the volume control pot mounted, the shaft in ( from the side ) , making sure there's enough room for the first cap on some tag board between the mains Tx and the choke. if only there'd been a way of somehow modelling the box and all the sizes and shapes of the parts, in 3D, before I started building :!:

#107 Re: Tweeter Amp for OB or Horns

Posted: Mon Jan 14, 2019 8:30 pm
by izzy wizzy
IslandPink wrote: Mon Jan 14, 2019 8:06 pm if only there'd been a way of somehow modelling the box and all the sizes and shapes of the parts, in 3D, before I started building :!:
If not this time then next time. Sketchup. Be glad to help. I use it to model things like this among other things.

Cheers,
Stephen

#108 Re: Tweeter Amp for OB or Horns

Posted: Mon Jan 14, 2019 10:02 pm
by IslandPink
You're very kind. Maybe one day the 4P1L>300B amp or a 4P1L>GM70 amp will need a box.

#109 Re: Tweeter Amp for OB or Horns

Posted: Tue Jan 15, 2019 8:20 am
by SimonC
IslandPink wrote: Mon Jan 14, 2019 8:06 pm .... if only there'd been a way of somehow modelling the box and all the sizes and shapes of the parts, in 3D, before I started building :!:
As Stephen says there is sketchup, and if you want something with a bit more power Autodesk's Fusion360 is well worth a look. Its free for non-commercial use and there are a lot of tutorials on youtube for it. Slightly more off topic, but I've been very impressed by the cam functionality that comes with it.

Simon C

#110 Re: Tweeter Amp for OB or Horns

Posted: Wed Jan 16, 2019 8:08 pm
by IslandPink
OK , I might have it.
Daddy Bear is in the inside, in the corner - we know that.
Mummy Bear will have to go outside, on the top, just near Black Gatey.
Baby Bear will have to go upright, attached to a bracket from the centre channel-piece.
Meanwhile the knob will come in the side, just near the rect...ifier valves.
Inputs will come into the top plate, straddling the centre-line.

#111 Re: Tweeter Amp for OB or Horns

Posted: Wed Jan 16, 2019 8:37 pm
by RhythMick
izzy wizzy wrote: Mon Jan 14, 2019 8:30 pm
IslandPink wrote: Mon Jan 14, 2019 8:06 pm if only there'd been a way of somehow modelling the box and all the sizes and shapes of the parts, in 3D, before I started building :!:
If not this time then next time. Sketchup. Be glad to help. I use it to model things like this among other things.

Cheers,
Stephen
Another alternative is Tinkercad.com which I used. SketchUp looks like it's more accurate, but that's probably just my skills lacking. Tinkercad I found very quick to get going with.

#112 Re: Tweeter Amp for OB or Horns

Posted: Sun Jan 27, 2019 8:11 pm
by IslandPink
Thanks. I'll see how I feel about trying it for the next amp ( phono or GM70 ) . To be honest, these days I have a morbid fear of forgetting how to do something else, if I learn some new software. I'm currently stuck trying to remember things about LT Spice.

Meanwhile, progress here this weekend. Wooden surround also progressed, will post a pic when the last ops on that are finished.
I need to post a new circuit drawing - I haven't caught up with the pentode bit properly, and yesterday I realised it would be a good idea to have a drop-down filter ( LC ) for the pentode drivers - hence the late addition of a small 9H choke near the output transformers - which I'm not 100% happy about, but we'll see. Currently digging in boxes for something nice for 16k anode load and ~100k screen dropper. Didn't plan my last HiFiColl purchase around this variant !
Tweeter_progress.JPG

#113 Re: Tweeter Amp for OB or Horns

Posted: Tue Jan 29, 2019 12:30 pm
by IslandPink
Circuit re-hash :
Tweeter_Amp_Jan2019.jpg

#114 Re: Tweeter Amp for OB or Horns

Posted: Tue Jan 29, 2019 1:11 pm
by IslandPink
Balls ! The 3.9u goes to the E83F cathode, not ground !

#115 Re: Tweeter Amp for OB or Horns

Posted: Sat Feb 02, 2019 11:46 pm
by IslandPink
I find it unlikely that I only bought 1-off Mundorf 3.9u/350 EVO and 1-off 0.1u/630 ZN cap.

#116 Re: Tweeter Amp for OB or Horns

Posted: Sun Feb 03, 2019 11:58 am
by pre65
IslandPink wrote: Sat Feb 02, 2019 11:46 pm I find it unlikely that I only bought 1-off Mundorf 3.9u/350 EVO and 1-off 0.1u/630 ZN cap.
Welcome to the world of old (er) age Mark. :lol:

#117 Re: Tweeter Amp for OB or Horns

Posted: Sun Feb 03, 2019 12:27 pm
by IslandPink
They are probably in the same place where the tools go to hide.

#118 Re: Tweeter Amp for OB or Horns

Posted: Sun Feb 03, 2019 3:40 pm
by IslandPink
ps. also, for 6AX4 , now 17AX4 :roll:

#119 Re: Tweeter Amp for OB or Horns

Posted: Sun Feb 03, 2019 9:56 pm
by IslandPink
Wood surround gave me the chance to get the wood bit and brace out to do the hole for the volume control -
Tweeter_surround.JPG

#120 Re: Tweeter Amp for OB or Horns

Posted: Mon Feb 04, 2019 8:40 am
by Ray P
IslandPink wrote: Sun Feb 03, 2019 12:27 pm They are probably in the same place where the tools go to hide.
Yep! Searched high and low for my fine rat tail file last weekend but to no avail so I popped down to the local Screwfix and bought a new one. Guess what was sitting on the work bench when I got back!