Can I use ROG Headphone mod on this Ruby Chubby?

Started by Gargaman, February 24, 2016, 06:11:43 PM

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Gargaman

I'm stuck here thinking about this.
I want to make a Ruby Amp with two separate enclosures. One for the input jack, power jack, battery, pcb, volume control and a headphone/out jack. The other one fits the speaker and a jack to it. I intend to have both connected by one of this pedalboard minicables.
How could I apply the Run Off Grove headphone mod in the 'headphone/out' jack  so that the resistor (in my case a 470R) can reduce properly only the headphone level? Will I have L and R  signal my phones with this configuration?
I also would like to ask about pluggin a stereo cable on the input, let's say from a mp3 player. I think this gonna mess around with the battery since I'm using the input jack to switch the amp on. Should I use a SPDT for power the amp on and off, and tie tip and ring of the input jack together to get stereo to mono?
I'm taking into account using adapters for 1/8 plugs, so I can use only 1/4 for the amp.
Here's a draw

Any idea would be appreciate,
Thanks!
Best regards

P.S. the headphone mod here http://runoffgroove.com/phones.png
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PRR

> Will I have L and R  signal my phones with this configuration?

You don't have + and R signals going IN.

The Ruby is a mono amp.

You could "mix" L+R to get a mono signal, so you hear both the violins and the cellos, all in center.

> tie tip and ring of the input jack together to get stereo to mono?

That often distorts. Depends what is driving it. If two "power amps" (even the small power amps in like an iPod), when L and R are not identical, they "fight", and distort.

> so that the resistor ...can reduce properly only the headphone level?

That's what the ROG connection does. The return path for the speaker goes right to common. The return path for the headphones must go through the 10 (or 470) resistor, which takes power away.
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Gargaman

> You could "mix" L+R to get a mono signal, so you hear both the violins and the cellos, all in center.
I was looking for a manner to do this and use the same jack for heaphone and for the speaker.
I believe it's impossible because if I use a switching stereo jack (like ROGs) and plug a mono plug from the speaker, my signal will be shunt to ground, right? Maybe using a switch to alternate between a speaker out and a phone out with only one jack.
> That often distorts. Depends what is driving it. If two "power amps" (even the small power amps in like an iPod), when L and R are not identical, they "fight", and distort.
Good to know!
Thanks, Paul, your patience with the dumbs is unbelievable.
I'll experiment a little bit more, maybe come back to tell what I get.
Best regards
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Kipper4

#3
I can't find it right now but the Deacy amp has a headphone and direct record mod. The Deacy has a similar 1watt output.
Be careful though some of the resistors are 1/2 watt rated.
Youll have to google it. I found a link to an eBay page with the schematic but it won't work from a link I'm certain.
Sorry if it's only half helpful
I'll pm Deano and see if he has a copy.

Also might be worth checking what needs doing with regard to the amps input impedance and the MP3 player as an MP3 players output impedance is bound to be differant to what a guitar is.
I could be wrong I don't have all the info to hand then again it could be OK.
Ma throats as dry as an overcooked kipper.


Smoke me a Kipper. I'll be back for breakfast.

Grey Paper.
http://www.aronnelson.com/DIYFiles/up/

Gargaman

Thanks for the effort, Kipper!
I'm very interested on such things like this Deacy and I'll google.,
I might be studying and learn about using different inputs for guitar, mp3, one amp per channel and  etc.
Wiring this stuff seems to be a little tricky too, grounding everything, understand how things works without jacks plugged in and so.
I'll keep it simple for this first one as a try, even without the headphone mod. Just the Ruby in two parts.

>Also might be worth checking what needs doing with regard to the amps input impedance and the MP3 player as an MP3 players output impedance is bound to be differant to what a guitar is
I'll pay attention about impedance too.
We can even burn a chip (amp) messing with its impedance along the speaker, can't we?  :icon_redface:
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Kipper4

I would say your unlikely to burn the chip but given your pyrotechnic history I can't say for sure.
You won't burn the chip by messing with the impedance.
Ma throats as dry as an overcooked kipper.


Smoke me a Kipper. I'll be back for breakfast.

Grey Paper.
http://www.aronnelson.com/DIYFiles/up/

Gargaman

It went hot when I was messing with two or more speakers, or the headphone mod. I think one got accidentally conect to the pin 5, bypassing the 220uF capacitor and zobel network. This proceeds?
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Kipper4

An all time favourite band of mine and Mrs Kippers
For you Gabriel.

http://youtu.be/u06DpcFXc4U
Ma throats as dry as an overcooked kipper.


Smoke me a Kipper. I'll be back for breakfast.

Grey Paper.
http://www.aronnelson.com/DIYFiles/up/

Gargaman

#8
Right, Kipper, the house is rocking!
I'm not too much into Talking Heads but i like David Byrne, it's nice.
One from my (not much my wifes) all time favourite guitarman
https://www.youtube.com/watch?v=FnYWfVPT5aI
So,
I draw what you guys suggested, a ruby amp followed by a Deacy headphone output. (without the direct record out).
DPDT to switch from headphone to amp.
I would like to know if everything is okay. Do I need to modify something, since it's a Ruby and not a Deacy?
I intend to use generic phones that are around 400/600 ohms.
Kipper, (I don't know if I can post the schematic here, but) I assumed that VR2 is a volume control for the headphones. As I want a fixed level for the headphone volume, I took out VR2 and C2 and put a fixed resistor R3. Is that ok?
Could I use my initial idea and put a jack in place of the speaker, so I can connect the amp to other cabinets?
thanks!
regards

I'm a begginer and really appreciate all helps here in the forum, even if you tell me to leave it away  :icon_neutral:
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PRR

> patience with the dumbs

You are not dumb. You are ignorant. Ignorance can be cured. (Partially cured... nobody ever knows everything, but we can each share some of what little we know.)

> use the same jack for heaphone and for the speaker.

Then they get the same signal. Which will be loud in headphones.

If 2 jacks is impossible, how about a switch to add the 10 or 470 Ohms? If you forget to flip, the speaker will be silly-weak, OK. The headphones will blow your eyeballs out, you won't forget again.

However since 1/4" is common and probably wise for speakers, while 1/8" has become common for headphones, why not two jacks? With resistor for 'phones. There is no trouble driving both at once, the headphone load is very light.

> post the schematic here

You can use a SPDT switch for 'phone/speaker switching, the ground can stay connected all the time.

You do not need R1, the '386 chip does not need a load (is a little happier without one).

A '386 chip on 9V can't make much over a half-watt output power in 8 or 16 Ohms, so if you do R1 it can be a 0.5W part.

You can probably omit R3, it hardly does anything.

You should be able to omit (short) R4 R5, unless you have headphones with mono jacks. (And then, it just won't play with plug full-in, but pull plug out halfway and it is fine.) If mono-phones operation is frequent, omit (short) R2 and put 200 (220) Ohms at R4 R5.

The 2.2uFd cap in this network is generally a bad idea. Power amps do not like to drive naked capacitors. (The 473 cap has 10r series resistance; the 220uFd output coupling cap has series resistance from speaker or 'phone-network.) While I would not expect the weak '386 to blow-up with a capacitor load, it may squeal or drain battery power needlessly.
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Gargaman

Thanks, again, Paul
>You are not dumb. You are ignorant. At least I know that and it's a good starting point!
I think I understand the most what you pointed, and there's even a lot of more information than I can take from these words, man. gratitude!!
I'm going with this

>The headphones will blow your eyeballs out, you won't forget again.
:icon_eek:
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Kipper4

Hurry up and build the sucker man. Your killing me already and let us know if it smokes.....
Ma throats as dry as an overcooked kipper.


Smoke me a Kipper. I'll be back for breakfast.

Grey Paper.
http://www.aronnelson.com/DIYFiles/up/

Gargaman

You are right, Rich..it's killing me too.
I went to buy some stereo 1/8 jacks.
at least, it's making sound, now to the offboard wiring.
https://www.youtube.com/watch?v=9-7iK-819ls
made a cellphone video from the breadboard (I was testing a fuzz and a delay in front of it)
Thanks again
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Kipper4

Did you trial the headphone out too while it's on the breadboard?
No magic smoke yet..... Always a bonus
Ma throats as dry as an overcooked kipper.


Smoke me a Kipper. I'll be back for breakfast.

Grey Paper.
http://www.aronnelson.com/DIYFiles/up/

Gargaman

#14
Just did that, Rich
The switch smokes switches!
Got a nice volume on the phones, both side.
A little background noise is more prominent on phones. I think it's normal, good enough for rock and roll.
I added the 104 capacitor from + to - that was missing on the breadboard. I can't hear its effect as I do with the 220uF,
but I'll leave it there.
thanks again!

Not using battery for this one, it's powered by a wallwart
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Kipper4

If the 100nf don't work try a much smaller cap 4.7nf maybe. It depends on what type of noise it is. But since it's on the BB it's gonna be easy to try.
Oh and remember things are often noisier on the BB than in a nice (faraday cage) enclosure.
Wall warts can add noise too.
Close enough for pedal testing though.
While your at it stick a 100ohm in series with the +9v (before the 100uf power smoothing cap) see how you like that.....
Ma throats as dry as an overcooked kipper.


Smoke me a Kipper. I'll be back for breakfast.

Grey Paper.
http://www.aronnelson.com/DIYFiles/up/

Gargaman

Thanks for the tips, sir!
I'll give them a try before enclosure. (only tomorrow, mrs gabriels home, no solder stuff) :icon_mad:
I've been discussing my noises along the topics, I'm learning a little by little.
This one is within my noise limits, but I'll try a smaller cap and the series resistor, specially to hear how it goes with phones.
Check out this 1/8 jack:

I was expecting to get some mini-jacks normal style, but this are cool.
All newbies jack should be like that so you see what's going on. :o
regards
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Kipper4

I keep a box of Jack testers for dummies like me.
A 1/4" trs Jack wired up with the leads ,marked up with insulation tape.
Insert the Jack in my Unknown pinout, new to me Jack .
Set the meter to beep connectivity setting.
And identify which lug is which.
Same for 1/8"
Din midi plug what ever you want to test.

Ma throats as dry as an overcooked kipper.


Smoke me a Kipper. I'll be back for breakfast.

Grey Paper.
http://www.aronnelson.com/DIYFiles/up/

Gargaman

Just finished the sucker!
Works like a charm  :)
I put the 4.7nF with the 100uF on power rails. Didn't notice any difference on breadboard, but now it's pretty silent inside the box, even on phones. I noticed that my laptop was sending noise to it, maybe my kitchen lamp too. Anyway, I got to study a lot about filters on power supply, frequency of noise, etc.
Sounds really clean with single coil, distorts a little bit more with humbuckers.
Thank you so very much guys for leading me through this! I'll post some pictures on the pictures thread.
Best regards
"My profile pic was stolen!"