Orange 86 Build Thread - no PCBs for sale

[guavatone]

Sounds like a DC Heater PS right?  It de-ends on your setup. If you’re using a 10 VAC  HEATER supply  you’ll be seeing about 13 volts before the regulator. 


Calculate your current draw for the LT supply.  The following is just for heaters:

Each channel pulls 1/2 amp for the heaters. If you have a 10V transformer for heaters you will have about 13VDC after the rectifiers.  We need to drop that down 4-5 volts to make life easy for the regulator(read, it doesn’t have a melt down).

For two channels I would parallel 2 8.2 ohm 5W radial resistors for 2a and 2b and jumper R1. This would drop volts by 5 so the reg will be happy, seeing about 9 volts.

https://www.mouser.com/ProductDetail/Ohmite/TWW5J8R2E?qs=sGAEpiMZZMtlubZbdhIBIO7UE9al6kwMwfAT6xANsRs%3d

For one channel at 1/2 an Amp I would use a 5 watt 8-10 ohm resistor in the R1 position and jumper 2a for the regulator to see 8-9 volts.

BTW, LDO voltage regulator need for this to work properly.


Note, if you are using a 300 mA power indicator lamp on the LT circuit we’’lmhave to make calculations for that, as follows.

2 channel would see 1.3 amps so 2 5W 5.6R in parallel in R2a and R2b positions will get you there. If the reg gets too hot you can add a .25-.5 Ohm 3 watt in R1 position to calm things down a half volt or so.

And 1 channel a 5W 5.1R axial will suit your needs.

Ohms law is your friend here.  Hope this helps.

 

[kosi]

helped, thanks a lot

 

[wmarden]

Hey Guavatone, I ordered what I thought was a stereo set of boards and what not but, apparently I only ordered a single channel, (1) preamp pcb set, (1) Preamp kit, (1) PSU pcb and (1) PSU kit. 


So my question is, to make the second channel in one enclosure besides buying another preamp pcb set and preamp parts kit, do I need to order another PSU kit?

 

[guavatone]

No. You just need another preamp set.  Feel Free to email me for any other questions.

 

[wmarden]

No. You just need another preamp set.  Feel Free to email me for any other questions.

Thanks!

 

[vmanj]

Greetings to all.

I assembled the HT power supply for Redd.47 according to the original scheme with oa2 regulator.

I have one question.
What will happen if this HT power supply is switched on without load, can oa2 fail (I mean physical damage, tube  explosion, etc.)?

 

[guavatone]

Hi vmanj> did you build an Orange 86 HT power with the TIP50 or your own point to point?  You may need to post on a different thread or start a new one. 

 

[vmanj]

No, my scheme is not Or86, it's assembled under the scheme r47. I thought that this was similar in general, so I did not want to create a new topic ...  :-[
But if my question is "inaccurate", then I will create a new topic for it.

 

[deuc224]

Hey Guavatone, I place an order for a set, are these still available?  Plan on doing  a few more if they are available.

 

[guavatone]

Yes. I’ll shoot you an email

 

[deuc224]

Perfect!!!!!!!

 

[Moose]

This is an old thread but still seems somewhat active, so I'll take a swing.

What's the consensus on tubes here?  I'm thinking e88cc or equivalent, EF86/806 for the pentode.  I'll be using Cinemags.

Anyone have favorite brands? Is a decent NOS worth it? Does it make a difference? I'm not spilling $400 a pop for the prettiest Telefunken on the ebay, but I'll spend a little extra if I can be convinced it matters. Saving $50 here or there  putting in valves that don't sound as good after dropping a couple hundred extra on quality parts seems like a false economy.

But tubes and the differences they make are a funny thing. I've built a lot of tube stuff and tried a few different brands new and NOS, and I can definitely hear it in some amps and mics, or in some POSITIONS in an amp, while others are pretty tube agnostic. So since I haven't experimented with this circuit yet I thought I'd ask for opinions.  What's going to give me great sound and low noise?

 

[alexc]

I've been using, for the longest time now, the russian 6J32P and 6N5P combo...  it works very well indeed in this classic circuit.

The orange86 main board hv section is rock solid and is just idling almost .. that and very nice and uncluttered pcb layout results in very low and stable noise floor.

SO - me, myself, I  use an orange86 pcb in a 2ru as my main 'experimental' platform for preamps, eqs and such. ....  and primarily as my goto tube DI box  8) 8)  It is so quiet and rich sounding  ....

.......

I've just upgraded the output traffo to a local (Aust.)  60s broadcast fav .. real classy, heavy and shielded unit  than can do 30K/600  (or 7K5/600)  ....   

and it has cleaned up some more, from the previous config with the Edcor xsm 15K/600 line output ... 

(there is some difference in overall level according to output tube and traffo selections)

This Trimax unit in 30K/600 has huge bass, no shortage of hi freqs either ... 7K5 similar but with some more gain!

The Edcor is very good performer, measurement and listening wise ....  and the system overall measures up very well, as one would expect, what with the nfb(s)  and such ....  at the price of entry, the orange86 with edcors and russkie tubes is a winner.

BUT  I'm just now, with this nice Trimax in place, I'm  going to splash a bit and get some couple  of tube equivalents ... for rolling  It sounds so good, it does.

I use a very capable german psu toroid, a jlm 3 way psu module and a dc heater supply with a lot of r-c  filtering, so no problems whatever with psu ...  either hv or heater ...  and my case can take the somewhat taller tubes  ....

...

Well the basic ef86/au7 combo is very well defined and pleasing to many around the globe. The russian 6j32p sub for the pentode is just fine. Subbing the au7 for the 6n5p is similarly fine if you have the available additional heater current.

I like to roll around the au7 ...  I have a bunch of nos and modern types ...  they are mostly good, the modern types usually measure better  .... 

Here I am now listening to the nos  ge6829, a slightly taller bottle with more heater current,  and I have to say I'm liking it; when I measured it up, it gave pretty good numbers ... as quiet as the best nos au7 and typical modern versions, but with a little less thd for the same output level  ...  strong h2 component with lower h3  with similar  regular, sparse higher order spectrum

I could also use a higher mu triode if I want, say the av7 types, with the 30K/600 option  ...  the higher gain offsets the larger stepdown and the higher internal plate resistance is offset by the higher primary impedance (and inductance).

For now, the rolled sound is exciting enough for me to get a couple more input pentodes to play with  ... some E80F or EF806  tall bottles, for example  .. perhaps a nos EF86 if I can find interesting deal.

..

It's all pretty good with this classic preamp topology    .. hard to go wrong, in fact!

I use my orange86 platform mostly for guitar/bass DI .. but I do have phantom power and a utc 0-9 + sheild  for mic inputs (250-15K with switched primary and/or secondary taps). 

I like the super quiet, smooth gain/thd  variation- I have added a hairball t-pad after the output traffo to give me extra control.

I'm planning to add a simple switch for the main coupling cap, to select a few different values .. as a simple hpf  ...

I have to make a new attempt at an 'eq+drive' module (would make it my 3rd attempt!) ..  basically a bax with gain 

 

[guavatone]

Hello All good REDD addicts. I’ve been diving into modifications of this project. I’d like to call on people to try the following mod.  I A/B’d it to another Orange 86 that is not identical but i’m Really liking it.

It involves the screen Voltage and using a zener to clap it at 65-85 V but you need to change R15 from 51K to  22K and R7 to 82K. Then you take 1 or 2 Zeners 1/2W  and put 1 100nF-470nF cap across them to replace C3 With the lines pointing towards  the relay. I used  a 20V and 39V Zener and got 67V.

I’ll update more, but I think the designers just used data sheets on this and neglected the screen voltage.
The Plate sit at 73V or so and it doesn’t make sense that the screen would sit 10-20V higher than the plate. But more importantly is how it sounds. One could do a quick mod  and change R7 to 470K to 510K. But part of what i’m Hearing is the clamping of the Zener.  I think V72 engineers knew what they were doing when they used a voltage divider to clamp the screen voltage on their first stage pentode.

I find the result to be more open and airy sound and less constricted. I’d be very curious what others think about it on their recordings.

More mods to come.

 

[rock soderstrom]

Very interesting, please continue. Cheers

 

[vmanj]

-  alexc  -

- // I've been using, for the longest time now, the russian 6J32P and 6N5P combo...  it works very well indeed in this classic circuit. //

And your heaters 6.3V - AC or DC?

 

[deuc224]

I cant seem to get cinemag to get me the transformers.  I was told it was a 2 week job and next week itll be 3 months and still nothing.  Does anyone recommend someone else to get transformers from?  BTW i was planning on getting some tung sol ef806 tubes and gold lion 6922.

 

[alexc]

I use DC heaters on my Orange86 builds ...

Full wave high-power bridge with C-R-C filtering, going from 9VAC which gives around 9Vdc loaded.

The caps are usually 22KuF 25V and the dropper resistor is 15W to 25W aluminium, calculated to  drop 2.7V at the desired current. The rectifier bridge and resistor are mounted on the chassis for heatsinking ...

Ripple comes out pretty low - no regulator required, and the result is usually pretty reliable.

 

[vmanj]

- alexc -

I understand you.

I have 3 Tubes of 6J32P and all 3 of them have some marriage.
On two of these Tubes (1981), there is a "hum" - on one tube more and on the other less.
On the third 6J32P (1967) - there is no "hum", but there is some fractional noise.

Earlier, when I used DC Heater, then on my 3 Tubes 6J32P there was no "hum".
Next, I decided to remake the power supply in the original scheme with AC Heater and Oa2.
With the usual EF86 everything works fine, but my 6J32P - fail ...


Maybe I'm wrong, but I think that these 6J32P Tube have a wide range of characteristics or a marriage (for AC Heater), unlike EF86 ...
But to find out, I will need to try different EF86.
For now, unfortunately, I have only one EF86, but if I have such an opportunity, I'll try to do it.

 

[vmanj]

-  deuc224  - 

Three months - it seems too long ..

I ordered transformers from Sowter - 9970 and 9980.
For a little over a month, I received them.