Orange 86 Build Thread - no PCBs for sale

[baadc0de]

+1 for the dual option

 

[studiosteve]

There is a 70% chance I'll be working with par-metal to make some.

ditto that. I'd like to see a case that would hold two of these preamp PCBs.

 

[guavatone]

There is a 70% chance I'll be working with par-metal to make some.

ditto that. I'd like to see a case that would hold two of these preamp PCBs.

Par Metal's

10-19143x
10-19145x for 12BH7 output

These are the 10 series 14" deep.

 

[guavatone]

Hi there again,

Can someone confirm these things:

1. C7, C9, C15 HT Bypass Caps 3 MKS4-.1/630/10 Wima 15mm LS - Are here enough 250VDC caps?
2. What is the value of C1 on DI PCB?
3. What are the value of these on PSU PCB? D14? D15? R15? C19?

Thank you very much.

1. No 300VDC or slightly less run on those, so minimum would have to be 350VDC caps
2. No need, just for tweakers
3.  D12-D15 just basic 1N4004, 1n4007 or alternative that can handle 100V
C19... that section is for tweaking. just bypass with jumper and ignore C19 and R15

BTW, can you see these values on the schems?

Thanks, I will revise BOM to include PS diodes that are missing

I will have to revise the docs for more PSU info.

 

[studiosteve]

Thanks, I will revise BOM to include PS diodes that are missing

I will have to revise the docs for more PSU info.

Hello to all. Speaking of BOMs, I've downloaded the rar file from the head of this thread, and I'm not seeing the BOM for the preamp. I only see the BOM for the power supply. Should I be looking elsewhere?

And on the same subject, I keep seeing mention of corrections to the BOM (which is good!). When this happens, should one go back to the rar file at the head of this thread and download again?Thanks.

 

[imo]

Will the Edcor power XPWR097 feed your heater/relay/48v board from the 10v winding. I am trying to pull my mouser/Edcor order together, and trying to decide on a couple of routes.

 

[guavatone]

The Edcor feeds the DC heater but the onboard XFMR that you can get from mouser feeds the P48 and relay power.

 

[briomusic]

Having built a few SSLs and EZ1290s, I feel like moving on to a tube pre-amp. 8)
Since Drip is currently submerged in 660 land and doesn't sell any mic-pres at the moment, this seems to be a good choice for an entry level tube-pre? I had a quick look at the great documentation and think I could hack this....

I would be even more tempted if I could get hold of the iron in Europe - does anyone know if there are equivalents to the Edcor and Cinemag transformers from, say, Sowter or Carnhill?

Also, this seems to be a very fresh product in more than one way Has someone successfully completed a build at this point?

 

[guavatone]

Check out Sowter the 1:7 and the 7:1 redd47 transformers
models are 9970 and 9980.  just use capacitor clamps to hold them down.

http://www.sowter.co.uk/cgi-bin/sh000001.pl?REFPAGE=http%3a%2f%2fwww%2esowter%2eco%2euk%2facatalog%2fsearch%2ehtml&WD=redd&PN=SOWTER_TRANSFORMERS_PRO_VINTAGE_TRANSFORMERS_5%2ehtml%23a148#a148

 

[briomusic]

Thanks for that guavatone. Now I just need to find something for this monster of a PSU tranny 

 

[guavatone]

Thanks for that guavatone. Now I just need to find something for this monster of a PSU tranny 

IT's not that much of a monster Power XFMR.  you only need 30mA per channel and add 10mA for overhead.
1 ch. = 40mA
2 ch. = 80mA
And the sceondary should be 275-0-275 Center tapped.  This will yield 388.85 VDC (275x1.414)
If you find one as low as 250 VCT (250-0-250) you will get 353.5 VDC which will be OK too, but you will need
to tweek to Resistors down in the CRCRCRC path to have less voltage drop across them.  (Sounds difficult, but quite easy)

Most High Voltage tube transformers will have plenty of Amps for AC heaters.  Though, you may have to run them on AC
which many gurus here believe is fine and that DC Heaters are superfluous.

Maybe try just one channel to simplify things.

How this helps.

 

[raysolinski]

Hey Charlie,
Did you ever tame the high frequency rise with the edcor output tranny? I had a tough time with that using an edcor in my Drip LA2a...bass rolled off and there was a high frequency rise regardless of termination although I did not try a zobel....dropped an old utc in there and it was  pretty flat so it wasn't the build. I guess if I end up doing this I could buy the sowters but they are pricey compared to the edcor's.

Thanks,
Ray

 

[guavatone]

Hey Charlie,
Did you ever tame the high frequency rise with the edcor output tranny? I had a tough time with that using an edcor in my Drip LA2a...bass rolled off and there was a high frequency rise regardless of termination although I did not try a zobel....dropped an old utc in there and it was  pretty flat so it wasn't the build. I guess if I end up doing this I could buy the sowters but they are pricey compared to the edcor's

Sorry Ray, I haven't.  Down the line, when I build a pre with 12bh7 tubes I'll try Edcor and see.  But for now I would recommend Cinemag.  

-looking at the chart, it doesn't seem so bad to have a 2dB rise.  I did get some 15K Edcors to test Wed. so I'll try that, since I feel it's more of an impedance issue.

 

[deuce42]

Without claiming to be an expert on this - I had no troubles with the edcors on my LA2A and am going to try one channel of my 0range 86 with the cinemags and the other with edcors.

The bass roll off a lot of people talked about seemed to be with the XSM series xformers but not the smaller and cheaper WSM's. Someone raised a possible theory on this board (an esteemed member here with a lot of knowledge) that the higher wattage XSM's series may have increased the capacitance hence the bass roll off. As for the high freq rise I noticed a slight rise but my ears didn't dislike it. I compared it to the Sowters and frankly decided I liked the Edcors. Given the price difference I wanted to like Sowters more and kept forcing myself to like them better. Eventually I accepted the stupdity of my ways and the edcors are still in my LA2A.

Like I say, I intend to do one channel of each on my Orange 86 and will report back with my findings.

 

[stitch-o]

Check out Sowter the 1:7 and the 7:1 redd47 transformers
models are 9970 and 9980.  just use capacitor clamps to hold them down.

http://www.sowter.co.uk/cgi-bin/sh000001.pl?REFPAGE=http%3a%2f%2fwww%2esowter%2eco%2euk%2facatalog%2fsearch%2ehtml&WD=redd&PN=SOWTER_TRANSFORMERS_PRO_VINTAGE_TRANSFORMERS_5%2ehtml%23a148#a148

What would be the difference in circuit using these as opposed to the cinemags?

Cheers!

 

[jyrki3101]

HI, I have some guestions about this Orange86 build ? 

1. R19-21 : 620ohm/2W.....are these values right for my dual channel build
  R18 : 200ohm/2W......same guestion about these too..
2. I read " MOV" on the PSU board. Does it mean a metal oxide varistor or........if it does, is it neccessary.
3. Output hookup : should I put a jumper on the O/P polarity board where it says " link"
4. I'm sorry for my bad english, but the wiring insructions say " splice both to shielded cable" in the output hookup diagram.
Unfortunately I don't guite understand that although I look at the picture. ...Does it mean that I should improvise and make the shielding myself somehow....( from a guitar or antenna cable???).......on some other builds those wires from main circuit board to OT are just twisted pairs......

                Regards. jyrki3101 

 

 

[stitch-o]

One other question as I get under way.
Consideration for designing the controls on the frontpanel:
-Gain (stepped attenuator)
-DI  (1/4" input jack)
-Squish - which would include a 500k pot and an on/off toggle switch
-Mic/Line(DI) switch
-48v mini toggle w/ LED indicator
-Phase mini toggle
-Pad mini toggle
-50ohm/200ohm input impedance switch ------- Ima call Cinemag today to see if this is possible with the CMMI-7C.---
the answer to this is yes. I just talked with Tom at Cinemag and this is fairly easy via a toggle on the faceplate. Switch between brown (high) and red (ct) lead, from pad PCB 'mic+'. Switch output of either brown or red is feeding the CMMI-7C. Orange (low) is constant connect from pad PCB (mic-) direct to cinemag input xfmr.

Cheers!

Another couple of questions:
C10-C14 appear to be snap-in EL caps on the BOM.
Should these have leads instead of a snap-in design?

On the BOM, the toggle switches for the POL and P48 are large and expensive.
Can I just use some Mountain mini-toggle SPDT switches instead?

6.3V lamp will be ok for T3 power indicator lamp?

Cheers!

EDIT: If the main gain switch is 12 positions, have those positions been measured to dB values?
I'd dig having them to label the frontpanel properly.

Cheers!

 

[guavatone]

HI, I have some guestions about this Orange86 build ? 

1. R19-21 : 620ohm/2W.....are these values right for my dual channel build
   R18 : 200ohm/2W......same guestion about these too..
2. I read " MOV" on the PSU board. Does it mean a metal oxide varistor or........if it does, is it neccessary.
3. Output hookup : should I put a jumper on the O/P polarity board where it says " link"
4. I'm sorry for my bad english, but the wiring insructions say " splice both to shielded cable" in the output hookup diagram.
Unfortunately I don't guite understand that although I look at the picture. ...Does it mean that I should improvise and make the shielding myself somehow....( from a guitar or antenna cable???).......on some other builds those wires from main circuit board to OT are just twisted pairs......

1.  Those values are correct if you are using the edcor and your primary voltage is close to 240VAC
2.  MOV is not necessary.
3.  Link links pin 1 to ground.  So yes, you should jumper both pads with a wire. Any lifting of shield cables can then be on the XLR cables.
4.  Generally the O/P XFMR cables will not be long enough and using a shielded cable will cut down crosstalk.  So splice means join cable by means of soldering them together to the extra shielded cabling.  make sure shield is only connected to ground at one point.

I hope this helps.

 

[guavatone]

One other question as I get under way.
Consideration for designing the controls on the frontpanel:
-Gain (stepped attenuator)
-DI  (1/4" input jack)
-Squish - which would include a 500k pot and an on/off toggle switch
-Mic/Line(DI) switch
-48v mini toggle w/ LED indicator
-Phase mini toggle
-Pad mini toggle
-50ohm/200ohm input impedance switch ------- Ima call Cinemag today to see if this is possible with the CMMI-7C.---
the answer to this is yes. I just talked with Tom at Cinemag and this is fairly easy via a toggle on the faceplate. Switch between brown (high) and red (ct) lead, from pad PCB 'mic+'. Switch output of either brown or red is feeding the CMMI-7C. Orange (low) is constant connect from pad PCB (mic-) direct to cinemag input xfmr.

Cheers!

Another couple of questions:
C10-C14 appear to be snap-in EL caps on the BOM.
Should these have leads instead of a snap-in design?

On the BOM, the toggle switches for the POL and P48 are large and expensive.
Can I just use some Mountain mini-toggle SPDT switches instead?

6.3V lamp will be ok for T3 power indicator lamp?

EDIT: If the main gain switch is 12 positions, have those positions been measured to dB values?
I'd dig having them to label the frontpanel properly.

Squish is experimental and not necessary, but it's up to you.  I would definitely have a switch to bypass the Squish altogether though.

It seems that you have the impedance switch sorted, though I wouldn't bother.
-the gain switch is measured to be pretty close to the correct decibels.
as follows:

46, 43, 40, 37, 34, 31, 28, 25, 22, 19, 16, 10
(the 10 dB mark is much less than the other increments as an safety feature for very high gain sources)

-the lamp should be fine.  but my lamp accounts for current draw, and may be something to consider.  Do you know the lamp Current draw?
500-600mA should be within range. 

C10-C14 are snap caps.  C11 and C12 have an option for leaded caps.

-Other cheaper switches should be fine.

I hope this helps.

 

[jyrki3101]

HI Charlie, thanks for your information. A couple more things which worries me a little:  ...there' a power link( B+) option on the main board....so....
which one would you recommend :  1. Solder all HT PSU RC-filtering components on both main boards on my dual O86 and power the 2nd channel from the auxiliary HT outlet on the main boare ?
                                                2. Use the Power(PWR) link for B+ (on main board) and leave out the HT filtering  components on the  2nd channel board?

3. E88CC valve : anode resistor value is 8k2/5W, I couldn' find any 5W metal film resistors and I used 8k2/ 3W, is 3W enough or if it isn't, from where should I start to look for that resistor cause I assume it can't be a wirewound type of res.( or metal oxide)?

4.In Zoebel network components list it says the 107k resistor is optional but what about the C-Z/20pF and  R-Z(30k), are these neccessary anyway?  With best Regards, jyrki3101