Orange 86 Build Thread - no PCBs for sale

[TimG]

I'd get a complex about it, except I really want/need to learn! And the advice is all constructive and correct.
It's a fundamental, no way around it.

I have a tremor which makes it a bit more difficult, but the only judge is the circuit!!
I've got time. And some other solder tips to try, videos to watch, and practice projects I can dip into.
Thanks!

(my future son-in-law said "you aren't going to leave that photo up are you!?!? haha)

 

[JMan]

I'd get a complex about it, except I really want/need to learn! And the advice is all constructive and correct.
It's a fundamental, no way around it.

I have a tremor which makes it a bit more difficult, but the only judge is the circuit!!
I've got time. And some other solder tips to try, videos to watch, and practice projects I can dip into.
Thanks!

(my future son-in-law said "you aren't going to leave that photo up are you!?!? haha)

Ah, I understand! There has definitely been some discussion around here somewhere about working with tremors. You may have been a part of those conversations, but if not, it definitely merits a search. You certainly aren't alone. Best of luck!

 

[guavatone]

I had an idea, now knowing more about the practical difficulties. Maybe try putting the iron in a vise and use your free hands to press the board onto it and feed more solder. I think that’s what i would try if I had shaky hands.
- keep with it, I admire your persistence

 

[TimG]

Thanks Charlie! If I get photos, I'll post them in the tremor thread! ;-)

 

[thelivingroom]

@guavatone, are these boards still available? I sent a request for them on your site, but I’m not sure if it went through or not. I’d love to tackle this one!

Thanks!
Chris

 

[TimG]

I spoke with him recently, I was hoping for an extra switch pcb (if anyone has extra?) and he said he didn’t have all his parts handy to check inventory.
It’s a great kit if you can get one.

 

[thelivingroom]

I spoke with him recently, I was hoping for an extra switch pcb (if anyone has extra?) and he said he didn’t have all his parts handy to check inventory.
It’s a great kit if you can get one.

Thanks @TimG. I heard back and it looks like I may be in luck! Time to read all of this thread again haha.

 

[TimG]

I heard back too! I fished my wish, and hopefully showing my work progress here not too far down the road!

 

[vitopower]

How do I find the impedance before the output coupling cap? I'm using the constant impedance gain switch and 470nf output and I'd like to determine an appropriate size output bypass capacitor that will have a -3db point between 6k-10k. I've found a calc that will tell me if I know this impedance, but I'm stuck. Plate resistance in parallel with plate resistor seems too low to be right, so is the feedback circuit affecting this figure?

 

[guavatone]

Hello all. I just updated the thread title to show I have no PCBs left to sell. I May do a v2 but that’s quite a bit away if at all. We may continue to use this thread for build help. Thank you all!

 

[guavatone]

How do I find the impedance before the output coupling cap? I'm using the constant impedance gain switch and 470nf output and I'd like to determine an appropriate size output bypass capacitor that will have a -3db point between 6k-10k. I've found a calc that will tell me if I know this impedance, but I'm stuck. Plate resistance in parallel with plate resistor seems too low to be right, so is the feedback circuit affecting this figure?

It’s about 14k close the the value of Plate resistor since it’s parallel. It’s been a while but here’s a nifty spreadsheet I made.

https://docs.google.com/file/d/1BgA...-YAuiA/edit?usp=docslist_api&filetype=msexcel

 

[TimG]

Thanks for helping me with the switch pcb! Grateful.

 

[thelivingroom]

Hello all. I just updated the thread title to show I have no PCBs left to sell. I May do a v2 but that’s quite a bit away if at all. We may continue to use this thread for build help. Thank you all!

Whew, I’m so happy I was able to get in on the tail end. I procrastinated for years on building one, mostly due to a lack of confidence in the past with understanding and sorting through the changes. This taught me a lesson to just start ordering boards for projects I’m interested in as they come up, and not wait until I’m ready.

One thing I discovered is that the switch on the Squish pot from Antique Electronics Supply that’s linked on the first post is open when “off” and closes when “on”, so I’ve designed some small relay pcb’s to add to flip-flop that action, as well as to convert the DPST white paddle switches I want to use to SPDT for the 48v switching. I’ll power those from the unused 12v section on the power pcb, as I have the others on 24v. I also designed a new DI jack pcb yesterday, because I ordered some white Cliff pcb mount 1/4” jacks to match the white knobs and switches haha. It was all a perfect reason to start learning KiCAD.

My boards are stuffed and I have several other pieces of the puzzle purchased. Just need audio transformers, tubes, case, front panel, and a secondary panel to mount the switches to. I went a little crazy with the splurging on Takman, PRP, and Kiwame resistors in many spots, as well as the caps on the main boards. Some may say it won’t make a difference and was a waste of $$, but I mostly just wanted a new challenge of sourcing parts over ordering the same ole stuff from my usual vendors. I figured if I’m about to drop $600 on 4 Sowters, plus the cost of the 4 tubes with today’s prices, then I could spend some extra on those parts, and this is a project that seemed worthy of it. Thank you @guavatone!

 

[guavatone]

Nice clean work. If I were to put HQ RESISTORS anywhere it would be plates on the pentode.

I like dales or similar RN65

 

[ElSmurf]

My boards are stuffed and I have several other pieces of the puzzle purchased. Just need audio transformers, tubes, case, front panel, and a secondary panel to mount the switches to. I went a little crazy with the splurging on Takman, PRP, and Kiwame resistors in many spots, as well as the caps on the main boards.

That looks a lot like my build, I also used Takman and Kiwame and went for the Mlytics in the PSU section. I love them for that usage.

No idea of any of that made any real difference to my build, I only know that my O86 sounds amazing. Very hifi, larger than life and smooth from top to bottom. Even a bit too much when I pair it with my D-EF47. But it makes my D87 really sing.

BTW where did you source those gold-plated Molex style connectors?

 

[thelivingroom]

That looks a lot like my build, I also used Takman and Kiwame and went for the Mlytics in the PSU section. I love them for that usage.

No idea of any of that made any real difference to my build, I only know that my O86 sounds amazing. Very hifi, larger than life and smooth from top to bottom. Even a bit too much when I pair it with my D-EF47. But it makes my D87 really sing.

BTW where did you source those gold-plated Molex style connectors?

That’s great to hear! I’m getting closer to finishing mine. I bought NOS Amperex EF86’s and Phillips PCC88’s from Christian Whitmore, had the pots and switches sub panel made as well as a trial front panel to check the clearances on my CAD work, finalized the front panel design, and received the relay and new DI jack PCB’s that I designed. Now I just need the Sowters, chassis, and front panel to be able to finally complete it.

The gold Molex KK’s are from Mouser. The 3.96 pitch headers I used are 26-61-4040, 4030, and 4020, and the 2.54 pitch are 22-11-2032 and 2022. The gold contacts are 08-55-106 (for the 3.96’s) and 08-55-102 (for the 2.54’s). I’ve since switched out the tin-plated KK’s in the photos that I had for power to tin-plated SPOX, since I had to order some for another project anyway.

 

[guavatone]

Very clean! Nice work!

 

[thelivingroom]

For those who have used the Sowter 9970/9980 combo, are the center taps left unterminated on the 9970 (orange, violet, and white), and secondaries on the 9980 wired in parallel (tie blue and brown, and yellow and white)? The sparse documentation from Sowter apparently expects me to be more knowledgeable than I am haha. Thanks!

 

[Bobby Baird]

On the 9970 input: Brown XLR2, Yellow XLR3, Green Out, Grey ground. Just isolate the center taps NC, and violet NC for 1:7 step-up ratio. The 9980 wire yellow and brown together to achieve 7:1 step-down ratio.
On the input in this example it appears the 9970 center-taps are used to filter frequency with zobel network. Experiment with the input. Output is straight forward.

 

[thelivingroom]

On the 9970 input: Brown XLR2, Yellow XLR3, Green Out, Grey ground. Just isolate the center taps NC, and violet NC for 1:7 step-up ratio. The 9980 wire yellow and brown together to achieve 7:1 step-down ratio.
On the input in this example it appears the 9970 center-taps are used to filter frequency with zobel network. Experiment with the input. Output is straight forward.

Thank you! If I’m understanding this correctly, according to this Orange 86 schematic I know I connect the secondary as Green to 2 and Grey to 1 on the PCB, then if I want to experiment with the center tap further I’d solder Violet (1:7 with the 34.5% tap) between the junction of R-Z and C-Z? As a side note, they’ve been adjusted to the suggested 470pf and 10k for the Sowter.