Re: Orange 86 Build Thread
« Reply #300 on: May 30, 2019, 03:34:19 PM »
I know it must be a bit frustrating but I think once we get the heaters sorted things will fall into place.

Again I need to know what kind of rectifier diodes are you using for heater supply.

Also, do you have any 3 amp or higher rectifier diodes on hand?

If we need to drop the heater supply we can fudge it with another diode drop

When you’re working on the heater power take D5 and reverse it. Jumper the 6.8 Ohm resistors.
Remove R3 R4 D6 and regulator. Reversing D5 will let us know how much Vf aka diode Voltage drop we’re getting.
You may also remove C5, C6 and VR1 While doing so.
« Last Edit: May 30, 2019, 04:16:10 PM by guavatone »


iomegaman

Re: Orange 86 Build Thread
« Reply #301 on: May 30, 2019, 06:17:24 PM »
Yeah no worries, at worst I get an education/wisdom, at best I get another great Pre/DI...at absolute worst I'll order another set and start over, although these boards are built like a tank!

I'll check my diode box I'm sure I have some very hefty power diodes...trying to remove parts now...

The rectifier diodes are VB7 HER 305's

https://media.digikey.com/pdf/Data%20Sheets/Diodes%20PDFs/HER301-305.pdf
Since the development of the internet millions of people have died, the two may or may not be related.

Re: Orange 86 Build Thread
« Reply #302 on: May 30, 2019, 08:34:51 PM »
I'll check my diode box I'm sure I have some very hefty power diodes...trying to remove parts now...
That info will be helpful. Are you using the same for protection diodes?

It’s not a matter of “hefty” diodes. I was curious if you had Schottky’s or other low Vf diodes.


This shows what these diodes will do at 1(red) and 1/2(blue) amps.  multiply that by 2 for the bridge rectifier diode drop. so for 1 Amp it will drop about 1.6V for 2 channels or 1 A current draw.  6.3x1.41 = 8.9  then 8.9-1.6 = 7.3 one more diode will drop that down to 6.5V. I would expect around 6.7 V since these transformers are 115V IIRC, and most Mains are closer to 120 these days.

« Last Edit: May 30, 2019, 10:51:54 PM by guavatone »

iomegaman

Re: Orange 86 Build Thread
« Reply #303 on: May 31, 2019, 12:26:24 PM »
I just found a small bag with 6 of the 1N5822 -3.0 amp schottkys....

.525 Vf...

plus a 3.6 and a 3.3 ohm 5watt resistors...my storage is a mess..

Will add and measure.
« Last Edit: May 31, 2019, 01:10:25 PM by iomegaman »
Since the development of the internet millions of people have died, the two may or may not be related.

iomegaman

Re: Orange 86 Build Thread
« Reply #304 on: June 01, 2019, 05:16:39 PM »
Pulled the HER305's dropped in some 3A 5 Watt schottkys that give me 6.5 on 2 channels...both under load...

Seems happy, gonna clean up and post tube voltages asap...thanks for all the help so far...love this build although it demands I pay attention!
« Last Edit: June 02, 2019, 10:02:40 AM by iomegaman »
Since the development of the internet millions of people have died, the two may or may not be related.

iomegaman

Re: Orange 86 Build Thread
« Reply #305 on: June 03, 2019, 02:30:57 PM »
Welp Charlie you were right! Got the psu settled in and everything is happy...I do have a pronounced hum that I am going to track down...one of the issues I discovered a b it too late was my original build was based on the 1.6 build docs and everything has been updated, did not see it until I looked at the psu schematic in the newer docs...you should see my original docs they are covered in notes and highlight colors...this was an amazing project and I love it.

And if you don't mind here's a thought and I'm looking for ideas:

So I originally built this using the edcor In/Out Tranx..they're ok, no real issues...

But last night I inserted an older vintage 1959 Stancor A4352 transformer I had lying about, it is a 1:13.3 dual winding push-pull /Mic/line to grid...plugged in my Tele and holy smokes it sounded like something right out Abby Roads...but when I disconnect the DI it has an unbearable hum mainly because of shielding, etc...but in DI mode it was super quiet, unbelievably quiet, I've never had a Tele sound that quiet and get that clean and loud in a preamp...wowza

I also have a super clean Jensen jt-13k7 which is only 1:5 step up...but it sounds super clean and gets great detail although lower gain...

What I would like to do is set up somehow on one channel to use the Jensen for mic input and the Stancor for DI ONLY...

Is this a matter of setting up another relay or do you have any ideas how I can mod this current setup to do this?

When I wired the Stancor I took the pad switch out of the circuit...with the Jensen being quieter I'm probably going to eliminate the switch altogether and maybe throw another switch in the hole in my faceplate instead...so I might just use a DPDT instead and try to remember when its DI...

I do need to get a better HF response with the Stancor though...seemed way to beefy but I haven't listed to it today so it might be fine...I just noticed C2 is 100uF I thought I read somewhere that it needed to be 220uf or higher? Or did I just imagine that?
« Last Edit: June 03, 2019, 02:46:36 PM by iomegaman »
Since the development of the internet millions of people have died, the two may or may not be related.

Re: Orange 86 Build Thread
« Reply #306 on: June 03, 2019, 02:54:34 PM »
I’m not sure what you are doing with the transformers and DI - because when DI  is engaged by the relay the input transformer is not being used, but rather, the signal is going direct to V1 grid.

Are you having poor HF response with the tele into the DI?

But one thing you can to get better HF response with the DI is put a 100p-220p cap at the point where the input transformer PCB connections are. It’s pretty easy to solder it underneath the PCB. Then put a 20p-47p cap near the V1 grid input. This will make up for higher guitar cable capacitance. Which may be what you are hearing.
« Last Edit: June 03, 2019, 03:01:30 PM by guavatone »

TillM

Re: Orange 86 Build Thread
« Reply #307 on: July 09, 2019, 03:08:26 PM »
the order page don't work anymore.
Is it still possible to get some PCBs ?

Re: Orange 86 Build Thread
« Reply #308 on: July 09, 2019, 05:14:44 PM »
Thanks for letting me know. Back in operation .
 
Sometimes when you edit jot form it chooses it's own generic URL.  ;D

 

Related Topics

  Subject / Started by Replies Last post
76 Replies
25010 Views
Last post November 03, 2010, 01:51:16 PM
by pH
73 Replies
32054 Views
Last post September 26, 2010, 01:51:30 PM
by SIXTYNINER
205 Replies
50613 Views
Last post April 22, 2017, 11:03:10 PM
by duantro
64 Replies
24918 Views
Last post January 09, 2017, 10:32:15 AM
by kosi