Thread: Progress - where are you at?

mmm lookin good there blacklabb
what circuit? or is it a home brew?

tag strip layout makes it easier to reduce capacitence i have heard as you can swizzle things about a bit?? dont know much but it wouldnt take much for me to go here
maybe start on an evatco kit

been looking a lot at ken fischers amps and i am getting that bug now

100 watts is a good size for bass but scary loud for guitar

thanks guys.

the preamp is my own design more or less. the preamp tubes have a pentode and a triode in them, so it's difficult to use a standard preamp, as pentodes arent usually found in guitar preamps. it has a split load phase inverter which is also pretty unusual. the phase inverter design is from a playmaster 116 (old australian amp). also the only amp i've seen with a 6bl8 used in it for instruments. aside from the PI the rest of the amp is different from the playmaster. the preamp goes input>pentode gain stage>volume> Triode cathode follower> tone stack >pentode gain stage + -ve feedback > split load phase inverter.

the tone stack can be lifted from the circuit, and there is a switch to change the -ve feedback values.

Now that looks good Mr Lab and as I like to make just about everything I can I would really like to know what your background is and how you went about making it, like where did you get the diagrams. The parts look second hand which interests me even more. What is the chance of you getting enough time to do post some "How To's" when it comes to this sort of stuff and what is the chance of hearing it when you have finished it. I have recently asked if there is any possibility of adding MP3s to threads and maybe it will be possible in the future. I did some sound on Biting Midge's "Penny whistle" Thread using YouTube you wouldn't need to add a movie like I did, you can just add a still pic using Windows Movie maker. Would love to hear it.

Jim

Also intersted in the Blacklabb adventures.
Apart from the engineering student side, tell us a little more of your adventures and your means therein.

parts are second hand toejam. the transformers i bought off a guy i met through ebay, who has alot of old transformers, as he buys amps and such that are not working for parts. the power transformer is from an old TV and the output transformer is from an amp of some sort. the choke is also from something made before i was born. the preamp tubes are actually designed for the tunign unit in a tv, but they work the same as audio stuff does.

amp diagrams are found easily on the net. www.schematicheaven.com has quite a few different ones. www.ozvalveamps.elands.com is one that is good for the australian valve amps.

as for my background, i just really like making things, and am happy to spend time reading and learning about things so i can one day make one myself. i got the urge to learn about amps when guitar wiring suddenly started to make sense to me. it made me think "this made no sense to me a few months ago, but now i'm happy to design my own guitar wiring, im sure guitar amps could be the same". i bought a book that went through guitar amps ( [ame]http://www.amazon.com/Guitar-Amp-Handbook-Understanding-Amplifiers/dp/087930863X ) which went from the real basics and let you understand what is going on in an amp. the most helpful part was the first few chapters which broke the amp down into the different stages and explained what they did and the circuitry within them. i also asked questions on designs on www.music-electronics-forum.com[/ame] which was a great resource.

i may write a bit of a tutorial on how to get into amp building, but i wont do much on the actual design or such, at least for now.

not sure what you mean by the blacklabb adventures oz tradie. is that refering to how i got into making the different things i make? if it is, it can all be linked to me being cheap and thinking i can do just as good a job as some company trying to make money off of me.


i

not sure exactly what is emant by the blacklabb adventures oz tradie. do you mean background into how i got into making the things i make?

You've pretty much answered what was the impetus to build your own amps.
That's what I was getting at, as well as more details about the journey in building one.
Like a guit. build thread but for amps.
Keep up the good work and new discoveries!!!!

an amp building tutorial would be awesome
just what i need... another project lol

I have similar leanings to you Blacklabb! Once you get an inkling that something could be an interesting challenge the reading starts and the fun begins.

Originally Posted by tim290280

I have similar leanings to you Blacklabb! Once you get an inkling that something could be an interesting challenge the reading starts and the fun begins.

i agree, the fun isnt just the building, its the whole preparation and planning way before hand that gets your heart pounding and your mind occupied. seems like true love, and then you finish making it, and you move on to the next one and barely have time to use the one that had consumed you completely.

was up until 5am finishing it off. just need to connect the mains and ground a couple wires. i just needed some spade connections, otherwise i;d probably be up until 6 setting the bias and seeing how many mistakes i made . i'll finish the connections tonight and probably set the bias before testing it as quietly as my excitement will let me, and then go to bed thinking of how it will sound at levels that dont choke the sound .

i'm borrowing an amp from a friend that he got a garage sale to use the tubes(seemed to be a homebrew with 4 6l6's in it, but has alot of hum so he doesnt use it, one day i'll get around to looking at it to see what could be done).
then i'll need to decide if i want to get 6l6's or el34's for the amp and buy them myself.

juat saying that the wiring is prettymuch finished, i just need to change a few values in the bias circuit to make it usable for many different tube types (at the moment its too low a voltage for anything really). i'll probably fire it up using a pair of 6550's, as i dont want to destroy my friends valves if something is wrong.

another update. the wiring is finished, but the bias pot i bought is faulty, and when i noticed it was too late to get another. the bias was set to max, so i tried it knowing it wouldnt sound very good like that. the first gain stage has an issue, but the noise of the multimeter was amplified from the stage after, so thats good. the issue may well be a shoddy tube, as i got them for free as they were pulled from old tv's. the first one i tried was bad as it put some voltage on the hot end of the input, so i wouldnt be surprised if this one is the same. i'll probably have to change the values of some resistors in the power section to get the voltages i want as well

Well it is not so recent, but I've not posted in a long time. I finished this guitar a few months ago. I was working on it with a professional so he was a very, very big help (no points for guessing who did the hard stuff)




I've got some other projects on the way (like a proper arch top) but working full time and spending my weekends either hung over or on a bmx tends to make them move pretty slowly.
A note to mods, sorry if the pics are a bit big, I did read the rules but I couldn't find pic size guidelines.

Hi LeonDanger,

Looks good. Got any specs on the guitar?

Cheers,

Peter

that looks great!!

very nice neck/body joint

string through is scaring me a bit though .. hmm