Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: craigtone on March 29, 2022, 12:30:02 pm

Title: Supro Coronado Build
Post by: craigtone on March 29, 2022, 12:30:02 pm

Thanks to a few members on this forum I was able to piece a schematic and layout (albeit backwards) for a 1690T build I'd like to do.  I have a good bit of experience with building tube gear, mostly hi-fi.  This is my first go with DIYLC and I really wished I had found this years ago!  Custom turret boards are WAY easier to deal with than tag strips!

Anyway, here is the schematic I used and my chassis drawing.  I'd appreciate any input since it is my first time using it.  I did find I had to save off the PCB to a separate file and move it to 0,0 in order to get the DIY Analyzer to see the board properly. 

PT will be 272FX, OT 125E to emulate the undersized OEM OT.  Chassis is an undrilled JTM45 and I'm hoping to find someone to fab a cabinet for me since finger joints are WAY outside of my ability!   :icon_biggrin: 

I haven't searched yet here but does anyone do custom raw cabs?  I have basic dimensions sketched up.

Thanks in advance!

Title: Re: Supro Coronado Build
Post by: craigtone on March 29, 2022, 12:47:41 pm

I just realized I forgot to hook the tremolo to the Ch2 V1 cathode ... fixed!

Title: Re: Supro Coronado Build
Post by: Latole on March 29, 2022, 12:51:04 pm

Cabinet;

No need to built a finger joints.
I built few no finger joints and they do the job. just need some corners and screw and glue and more time.

Finger joint is only the cheapest and solid cabinet you can built; need only glue
And they are fast to built if you have the tools

For any kind of cabinet, see you local carpenters or cabinet maker. Any onybody can built one for you, it is just a wool box.
Finish by yourself.

Title: Re: Supro Coronado Build
Post by: thetragichero on March 30, 2022, 07:41:50 am

i do box joints with hardwood dowels and wood glue. i like the idea of the base cabinet being 100% wood. eight right angle clamps make assembly easier

Title: Re: Supro Coronado Build
Post by: mk_716 on March 30, 2022, 07:52:52 am

FWIW, I've used butt joints with a Kreg Jig.   Use 1" screws  if you're rounding over the edges (not the recommended 1 1/4" if using 3/4 stock).   There's a pocket version of the Kreg jig that's pretty reasonable.   Great tool really.

Seems very solid.   I don't think I'd do box joints unless they were going to show on a stained/finished cab.

mike

Title: Re: Supro Coronado Build
Post by: bmccowan on March 30, 2022, 10:41:16 am

The Ebay vendors who sell finger joint or dovetail joint cabs will do custom cabs for you. I build my own finger joint cabs, its easy if you have the tools, but the part I hate is gluing on the Tolex or tweed. Although the contact cement hallucinations can be entertaining.

Title: Re: Supro Coronado Build
Post by: sluckey on March 30, 2022, 11:22:48 am

Here's another 1690T thread that you may be interested in...

     https://el34world.com/Forum/index.php?topic=27432.0

And here's a recent 1696TN thread. Very similar amp circuit.

     https://el34world.com/Forum/index.php?topic=28606.msg314945#msg314945

Title: Re: Supro Coronado Build
Post by: craigtone on March 30, 2022, 01:49:57 pm

Quote from: sluckey on March 30, 2022, 11:22:48 am

Here's another 1690T thread that you may be interested in...

     https://el34world.com/Forum/index.php?topic=27432.0

This is where I got most of my info.   :occasion14: