Valve amp build, anyone interested??

[arcdef]

As per title really, im building a valve guitar amp for my final uni project and instead of sticking up loads of pictures etc and finding no one is interested i thought id ask first.

So does anyone want to read this or should i go get my coat?

Ash.

[Wideboy]

yeah me!!!, i been thinking about building one for a while but not got round to it

[DarrenSV650S]

I'd be interested. Not because I'm interested in guitars or amps, just because I like techy stuff :)

[Kinvig]

Sounds like a pretty cool idea.

You may have ot also include an idiots guide - could be a summer project in the shed..... ;o)


....and please for the love of dog and everything holly, no cheesy graphics on the vloume control going up to 11 instead of 10!!!

[arcdef]

ok ill put together the pics and stuff and stick it up, im stuck with the front panel design at the moment, but dont worry the volume will be normal :).

[454697819]

My grandad gave me a schematic for one, and I think he still has the valves, I have just not ever been into electronics...

Crying shame really.

[SoulKiss]

This would be cool to see.

I'm starting to play with electronics - mainly using little ATMega series PICs.

Have already built (but not tested) a Pointy Gear Indicator.

[MCN_LiamM]

I'd love to see it.

[DarrenSV650S]

Have already built (but not tested) a Pointy Gear Indicator.
Interesting. How many pennies did that cost?

[SoulKiss]

Interesting. How many pennies did that cost?

Not saying :)

Not because I am being awkward, but because it was all done on breadboard with a fully assembled PIC Dev board (to get something that would run it ok you only need the CPU and a Timer), but I figure the materials for the controller come in at a huge amount less than the commercial ones, but I have no idea on how much it will be to weatherproof the display, and getting the same conenctors as are on the bike so that it just plugs inline may prove to be next to impossible.

Lets just say I have spent < £10 to date.

[arcdef]

oook so here goes, here we have all the parts required:

http://i62.photobucket.com/albums/h113/arcanedefiance/amp%20build/19062009154.jpg

So we have:

Power transformer
Output transformer
ECC83 Valve (plus socket and clip)
6V6 Valve (plus socket and clip)
Then we have all the resistors, capacitors, and some diodes but listing all the values would bore the hell out of me not to mention you lot!
Oh and all the obvious such as input/output sockets, volume, power switch/plug/light.

Ill post more in abit, it is lunch time :).

[DarrenSV650S]

Not saying :)

Not because I am being awkward, but because it was all done on breadboard with a fully assembled PIC Dev board (to get something that would run it ok you only need the CPU and a Timer), but I figure the materials for the controller come in at a huge amount less than the commercial ones, but I have no idea on how much it will be to weatherproof the display, and getting the same conenctors as are on the bike so that it just plugs inline may prove to be next to impossible.

Lets just say I have spent < £10 to date.


Hot glue guns are good at weatherproofing :)

If you produced them and sold them on ebay, they'd sell at a similar rate to hot cakes

[DarrenSV650S]

oook so here goes, here we have all the parts required:



So we have:

Power transformer
Output transformer
ECC83 Valve (plus socket and clip)
6V6 Valve (plus socket and clip)
Then we have all the resistors, capacitors, and some diodes but listing all the values would bore the hell out of me not to mention you lot!
Oh and all the obvious such as input/output sockets, volume, power switch/plug/light.

Ill post more in abit, it is lunch time :).
Don't know much about amps but I gather valves are better for sound quality. Will yours be a match for the new expensive amps?

[arcdef]

ahh yes, well back in the good old days before micro chips were invented they used to use valves to amplify the signal being passed through them, dont ask me how as i haven't figured that out yet (that will come soon for the essay!) and these are also how the guitars signal will be distorted as the level peaks. All the very expensive guitar amps normally use lots and lots of valves and people do say they are the best sound, but you can mix it all up and have solid state (all electronic boards) or have a hybrid mix of them.

Sorry if im confusing anyone, im kind of typing as i think!

And no i doubt it wil be a match for expensive ones as its only going to be a mighty 4W of output, along with being fairly basic (only two valves, no tone or gain controls etc) but i do hope to get a ncie crunchy distortion out of it.

[ophic]

I had a schematic for a Marshall Valvestate amp, which they freely sent me as I wanted to modify the effects loop. Not a true valve amp though - and there's lots of integrated circuits in there so its not all that useful.

Still I've built a few small amps with 741 op-amps, so I'm watching this thread with interest.

[arcdef]

I had a schematic for a Marshall Valvestate amp, which they freely sent me as I wanted to modify the effects loop. Not a true valve amp though - and there's lots of integrated circuits in there so its not all that useful.

Still I've built a few small amps with 741 op-amps, so I'm watching this thread with interest.

Would you be able to email a copy of that to me? Could be useful later on!

[SoulKiss]

Hot glue guns are good at weatherproofing :)

If you produced them and sold them on ebay, they'd sell at a similar rate to hot cakes

Trying not to derail here - the amp is the important bit :)

The only problem with mass producing them would be the fact that each CPU needs to be programmed.

When I do get it tested etc I will post up details for anyone that wants to DIY - but enough on this thread (although PM's welcome).

[amnesia]

I have my Marshall VBA400 in pieces at the moment, due to the valve heater current being higher than the wiring and connectors are good for.


...and I thought Marshall knew what they were doing when it came to valves!

You can get most of the circuits for Marshall amplifiers for free online. Have a chat to Google and he will help you out.

http://www.drtube.com/marshall.htm


ta-da!!!!!!!!!!!!

[ophic]

Would you be able to email a copy of that to me? Could be useful later on!
absolutely no idea where it is and it was on a single piece of folder A2 size paper! However as amnesia pointed out, they're available online, or if that fails, just phone up Marshall and ask, cos that's what i did.

[arcdef]

ahh cheers for that link lol slap me down for being lazy, Sorry!!!

The amp is coming along quite well now and have got the pics to stick up so far.

Here we go:

So first things first was to get all of the physical hardware bolted onto the chassis of the amp. This includes both the transformers, the valve sockets, input/output jacks, volume pot and power light/socket and switch!

This is the easiest section, if a little fiddly, and turns out something like this:

http://i62.photobucket.com/albums/h113/arcanedefiance/amp%20build/20062009155.jpg

As you can see, nothing too exciting but it shows where all the components sit and makes sense to do first so i can figure out cable lengths when i get to the wiring.

Oh and an inside shot so far:

http://i62.photobucket.com/albums/h113/arcanedefiance/amp%20build/26062009179.jpg

Next up is putting together the main circuit board. Seeing as i have never done anything like this before apart from putting a simple audio system together in my car boot this is where things got tricky for me. Figuring out all the little colour codes on the resistors takes time and making sure everything goes the right way is difficult!

Here is a nice bag of goodies!

http://i62.photobucket.com/albums/h113/arcanedefiance/amp%20build/25062009165.jpg

Opps, forgot to add the circuit diagram:

http://i62.photobucket.com/albums/h113/arcanedefiance/amp%20build/circuitdiagram.jpg

So anyway, firstly i figured out all the codes for the resistors, capacitors and diodes and simply laid them roughly where they had to sit on the board.

All of the capacitors laid out:
http://i62.photobucket.com/albums/h113/arcanedefiance/amp%20build/25062009163.jpg

Then again but with the resistors etc placed down as well.

Once all of this had been double and triple checked i began soldering each component to the turrets on the board.

which gave this:

http://i62.photobucket.com/albums/h113/arcanedefiance/amp%20build/25062009167.jpg

and then this: Forgot to add that i joined some of the turrets up with wire to use as a ground.

http://i62.photobucket.com/albums/h113/arcanedefiance/amp%20build/25062009174.jpg

Enjoy and if you have anything to ask please do, and anything that you think ive done wrong again, please say!

Cheers,
Ash.

[MCN_LiamM]

Can you do a step by step instruction booklet? :p

I'd love to give this a go but got no idea where to start.

[arcdef]

http://i62.photobucket.com/albums/h113/arcanedefiance/26072009257.jpg

Just a taste of what it looks like now, its all done, and sounds very good may i just add! Once ive got all my work handed in i will write it up properly for those who are still interested, and those who arnt, tough!

[empty]

By the looks of the circuit diagram, you've got an all class A amplifier, so the output power is going to be on the low side, hence the warm sound (plenty of distortion).

For anyone thinking of making something similar, do be careful, the output of the bridge rectifier is 400V (or there abouts) and a fair bit of charge will be stored in the capacitors.

MT

[arcdef]

yep, its a single ended class A design, and it has voltages up to around 380V. output power is a mighty 4W, but it still managed to fill the house with lovely valvey goodness earlier in testing :D, would say its equal to that of a 15W solid state in terms of volume, and again yep lots of nice crunchy distortion.

Next challenge will be something with lots of high gain along the lines of a TSL if i can find the right schematic!

[Jayneflakes]

:D ooh ooh, wanna see more piccies of finished object... Perrrrrrrleeeeeeeeease? :D

I make electronic handbags. The last one was very cyber goth with a PIC powered Nightrider style red swoop. Ta Carla for making the program for me. :p

[warg60]

Good grief I never thought I would be looking at circuit diagram with valves in again :)
Good luck, I hated valves circuits as I was always getting "bit" by the HT. Ironically, 350V is worse that the 25kV I got off a few CRTs now and again, not that I recommend get zapped by either (we were always trained to work with one hand in our pockets so that we didn't create a circuit across our hearts to ground).