Help with schematic

[Dackzy]

I am trying to make a schematic of a PCB. I need it to look like this one, but I cannot find anything that has a 7 pin tube socket.

Spoiler

 

I would greatly appreciate it if someone could help me or make it for me  

 

[dany_boy]

Hey, check Dave's video:

He does exactly what you ask for (and more).

Cheers!

[mariushm]

If you don't know what you're doing, you should stay away from projects like this one.

You're working with relatively high voltages (anything over 24v is considered high voltage and dangerous, and this amplifier requires 48v) and you're using up to 15 watts or so to produce around milliwatts of power into your headphones

 

If you want something hi-fi , I'd suggest using something like the class AB amplifier chip TPA6120 .. you have schematics and even circuit board layouts here : http://www.pavouk.org/hw/tpa6120headamp/en_index.html

Chip is easy to find and relatively cheap , around 6-8$ at Digikey or farnell, where you can also buy the other parts like a standard transformer with two 15v secondary windings and 10+ VA rating, in order to create your +/- 12v  split power supply. 

[Dackzy]

40 minutes ago, mariushm said:

If you don't know what you're doing, you should stay away from projects like this one.

You're working with relatively high voltages (anything over 24v is considered high voltage and dangerous, and this amplifier requires 48v) and you're using up to 15 watts or so to produce around milliwatts of power into your headphones

 

If you want something hi-fi , I'd suggest using something like the class AB amplifier chip TPA6120 .. you have schematics and even circuit board layouts here : http://www.pavouk.org/hw/tpa6120headamp/en_index.html

Chip is easy to find and relatively cheap , around 6-8$ at Digikey or farnell, where you can also buy the other parts like a standard transformer with two 15v secondary windings and 10+ VA rating, in order to create your +/- 12v  split power supply. 

4

m8 I know what I am doing, I just cannot find the tube.

Also why do you even link to that amp? It has nothing to do with this topic and as an amp it isn't even worth me looking at it. I want to make a decent quality hybrid tube amp and all I need is the PCB.

[mariushm]

I linked to that because you'll get the same amount of quality (or even more quality) with that chip, compared to using some potentially ancient tubes and complicating your life with 48v power sources (not as common as +/-15v or +/-12v sources.

 

It's not a class D chip, it's class AB so linear, the power supply can be made linear as well if you don't want audio artefacts from switching power supplies or pwm in the amplifier chips

 

Yeah, I guess if you just want to make something with tubes, you can ignore my message. Just pointing out it's possible to get same or better quality in a much smaller amplifier.

 

if you can't find the tube itself ... they're old, what to you expect... You can find on eBay those tubes, old stock from the 1950's or clones/fakes.. if you think something made in the 50's will make the amp sound better than a modern chip... 

If you mean the actual footprint for the pcb, you typically do it yourself in the software you use (eagle, diptrace. altium, zuken, orcad, whatever) .. buy one of those tubes and a some ruler and measure the distances between the pins and make your own footprint

If you're lucky you may find the footprint in some free libraries for your particular software you use to make the boards.

[Dackzy]

Just now, mariushm said:

I linked to that because you'll get the same amount of quality (or even more quality) with that chip, compared to using some potentially ancient tubes and complicating your life with 48v power sources (not as common as +/-15v or +/-12v sources.

 

It's not a class D chip, it's class AB so linear, the power supply can be made linear as well if you don't want audio artefacts from switching power supplies or pwm in the amplifier chips

 

Yeah, I guess if you just want to make something with tubes, you can ignore my message. Just pointing out it's possible to get same or better quality in a much smaller amplifier.

 

you see it might give the same power in the end. The sound will be very different and ofc the quality of the signal that the hybrid is among the best in a 300$ hybrid tube range, yes ss amps will have a cleaner signal, but you never make a tube amp if you want a clean transparent signal.

 

I already have an audio-G/D NFB11 on the way, so I want a hybrid tube amp that I can switch to when I want to and ofc it has to be hybrid or else it wouldn't have any power in the lower Ohms

[cameroncoats]

On 08/04/2017 at 9:52 PM, mariushm said:

If you're lucky you may find the footprint in some free libraries for your particular software you use to make the boards.

Trap for young players - if you're lucky enough to find one triple check every single dimension to make sure it will fit your parts.

 

I have been bitten by this more than once; there's nothing worse than having to work backwards and find parts that will fit your PCB

[kasugatei]

Back on topic. DipTrace has nice new component maker. There is a video tutorial on their web page.

In case if it is not in a library already.

[yathis]

On 4/8/2017 at 1:56 PM, mariushm said:

24v is considered high voltage and dangerous

24Vdc is pretty low and wont break the resistance of the skin.

I work on ebikes and I stick to 72Vdc and nothing over 100Vdc.

 

Remember its the amps that kill you and not very much, but you need a certain voltage dc to break the insulation factor of skin.

 

 

 

[mariushm]

5 hours ago, yathis said:

24Vdc is pretty low and wont break the resistance of the skin.

I work on ebikes and I stick to 72Vdc and nothing over 100Vdc.

 

Remember its the amps that kill you and not very much, but you need a certain voltage dc to break the insulation factor of skin.

 

 

 

No, it's a combination of voltage AND current that kills you. You can't have one without the other. You can have 100A at very low voltage and won't pass the skin and you may not feel it if you touch the terminals with your fingers, or you may have high voltage and very low current (think experiments in school with that machine that made your hair float in the air) and you'll be fine.

 

 

24v is the threshold above which companies often have to submit products for third party certifications and tests (instead of self certifying) and in case of some applications it's downright now allowed (like in a computer, can't have power supply output more than 24v as the user could easily short pins in connectors and crap like that, it's too easy to hurt users). That's one of the reason why you can find plenty of switch more power supplies with up to 24v at the output but much fewer above that voltage (except 48v which is used a lot in telecommunications and power over ethernet)

 

Technically "low voltage" is anything between 120v and 1500v DC , see https://en.wikipedia.org/wiki/Low_voltage - obviously I wasn't literal.

 

[yathis]

9 hours ago, mariushm said:

No, it's a combination of voltage AND current that kills you.

Yes I said that.