Hi askwho69. Welcome to the forum.

Let me try to answer your question.

I can see in the MG squematics posted here, that V+ comes from CN3 at 13,14 and 15 pins. In the same way, V- comes from 10,11 and 12 pins.

If you check the TDA7293 Datasheet , in the first page, you´ll see that the chip receive V+ at 7 and 13 pins and V- at 8 and 15 pins.

So, if you connect CN3 with CN1 as you says  (1-1, 2-2, ...., 15-15) you´ll routing V+ and V- to the right pins of the chip.

Hope help.

Regards.

Yes!!!! I like it!!!  Very cool sound!!!  :tu: :tu: :tu:

Maybe i´ll copy and paste!!!!

Quote from: KMG on January 28, 2011, 07:01:48 AM
I'm not a good guitarist to record samples. Wait untill my friend will come to visit me.

I´m no so far away of your playing skill, but i think that anybody that stand up front a Marshall can´t resist to play (and want to ear too) is a A5 chord at full power 

Wow man!!!  Awesome work!!!

It´s look very professional.  :tu:

Perhaps can you post some sample sound of it?

Quote from: J M Fahey on December 08, 2010, 07:55:41 AM
Download the excellent: http://www.vellemanusa.com/downloads/0/illustrated/illustrated_assembly_manual_k4001.pdf
For comments: http://www.ssguitar.com/index.php?topic=1834.0

Hi J M Fahey... had been a so long time...

May i suggest to use at our friend a TDA2005? TDA2005 Datasheet

It is practically the same effort to make and its twice the power of TDA2003.

I mounted a poweramp using the datasheet circuit, and it worked very good  :tu: :tu: !!!

If is worried about controling the volume output, maybe you can copy the same concept of the illustrated_assembly_manual,  i mean use a potentiometer conected as show, at the input.

Regards.

Hi guys:

Its a long time since my last post. Im had been working a lot. (thanks god).

I maked a TDA2005 amp, and used a marshall bluesbkr clone as a preamp. Its sounded very nice for my, but i made the preamp with a universal pcb, so it isnt  very reliable, so.. sometimes worked, sometimes not.

I have a radio program too, where we and our guests, just play a backgrond track, and just jam over it. We use a Marshall VS102 of my partner, conected to the studio console. It sound very good  <3)

Cause of the sound of it, i get the plans of it from www.drtube.com, and begin to study it.  It has 2 channels.It has one clean, and one overdrive channel, each one selectable, and the overdrive is switcheable beetween OD1, and OD2.  Kind of two differents overdrives. I thinking (and planning) to make some kind of clone of it, but, its has some ICs that i cant get easely. It is the M5201 wich are a dual omp amp selectable by tension. It use too a 4316, wich are apparently a cuadruple switch.  They use those IC, for switch beetween differents chanels setup. i.e, in the overdrive first opamp chanel, they use the 4316 for setup differents gains loop for OD1, and for OD2.  Another case of use of the M5201 is when they select clean or overdrive chanell.

I wondering if its razonable to use some relays and simple TL07XX instead of them, properly wired. Electrically i think that is no difficult to make that changes, but since of point of view of the signal quality or better to say, sound quality, i afraid if it will causes no troubles like pops sounds when use the relays for change the channels.

Please, can you say something about this?

Thanks a lot for your help.
PD: I making a box for all the stuff. When i finish it i ll post some pictures, im promises.

Hi everybody there:

Since last year that i don´t write any post, so happy new year. I back again, and have some to tell you.

Following my "roadmap", i already maded a Ruby with a tone control big muffed style with pretty success. (Coihue Micro).  I had learned that for my, about 50% of the sound is the speaker.  After, i used the ruby like a "test amp stage" for severals pre. I tryed ROG thor, thunderchief, and tonemender, with some succes just with the tonecontrol. The others, well,  :grr  Reading the forum, that circuits, no work at all, so, i put them a side.

Then, i made a TDA2005 datasheet BRIDGE power stage using a power supply maded with a rectifier bridge and a dicroic feed tranny. (about 50VA)  It work pretty nice, using just a buffer stage with a MPF102 direct from the guitar, and i sound very nice, clean.  Regrettably, in that time just have a cheap 6" speaker, so it sound like sh... when i hit hard the strings.

Since about two weeks, i purchased a 12" - 8 ohms speakers at J M FAHEY and with it, is a peace of cake <3).

I used like preamp, then, a Marshall BluesBraker clon, mounted over a perfboard, and it works no so good, (when it worked).

I planing to etch a board of that Marshall BluesBraker, then see what append.  I looking for a versatile circuit of a preamp, that gimme a "marshall-like" sound, (going from nice clean, to medium distortion, Hells Bells?, you know?) with a good tone control, and foot swicheable distortion, and a effect loop.



I founded the circuit of a Trace Elliot SuperTramp, and looks pretty nice, but, no idea that what FET them uses...


Any suggestion about a circuit?

Founded a good pre, next step is make a TDA7294 power stage.

Hi:

My 2 cents answer...

If the output says that is 8 ohm, you could conect to it any cabinet or speaker that have an impedance of 8 ohm or more than this, i.e. 16 ohms, no matter the size of the speaker or cabinet.

You *dont ever* should conect any speaker or cabinet with an impedance less than 8 ohms to it, cause you ll pushing out of your PA more power that it can handle, so you ll probably hurt it.

Power[w]=Tension [v]* Current [a],  and Current = Tension / R(impedance)[ohm], so as R is lesser, I is bigger, and so is bigger P. Making R(your speaker or cabinet) leeser you ll trying to get for more power that you PA can give.

Hope usefull answer. Maybe somebody can fine tune my english and concepts.

Hi:

I looking for a nice preamp for my future amp and founded this....



May ask what our masters think about it?

EDIT: Done. Loaded the jpg.

Hi there:

Some question stickin in my mind.

I had been looking for a cheap tranny for a simple power stage made with a TDA2005 like its datasheet, bridged version, and i wonder if a can use a transformer that i seed used for feed dicroic lamp, cause....

a) a 220Vca-12Vca 5 amp transformer worth around $70  ( +- 17 u$s)  (electronic stores)
b) a 220Vca-12Vca  50W for dicroic lamp sales around of ¡¡$16!!  ( +- 4 u$s )  (electric stores)

I think that the fact that factories make hughes mount of dicroic lamp transformer they are very cheap.

Is 50W (around 4.16 A) enough for a TDA2005 bridged?

thakns guy for your pacient answerings

regards

Very nice amp!!

Congratulations!!!

Hi everobody:

Im just curious about something:

Why regular SS Guitar amp (at least that i see here, in Argentine) dont use tweeters?

Any idea?

HI Joe:

I wondering if the 4 wires at the "pseudoprimary" maybe means that your tranny have two primaries windings. The fact that they are joined make me suspect this. Maybe black and white is one winding and red and brown another. Other posible combination is black and brown, one winding, and white and red, another.


Perhaps your tryied measuring with a tester continuity between each pair of wires?

Hope helped

Thanks JM. Good answer. Then...im looking the differents answer that i got of us, and wondering now if i got this right.

I already started another topic asking for a "just one preamp stage driving two identical power stages" and looks like it is posible.. Looks that isnt a bad idea at all.

You had confirmed that i have a good PS enough for two 7294 power stages.

So, the roadmap that i planning now, is....

-At first try, i ll make just one power stage, use the " 8)Coihue micro "  as a preamp and see if them are enough power to play with the guys.
-I ll keep another "ace in the hole" (it is right?) and, if i short of power, add one more power stage with one more speaker.

that all....for now...

Thanks a lot at all you guys... i learning a lot, and getting comforting little success

Hi:

I had been studing the TDA7294 datasheet and noted something that im in doubt.

At the page 6/13 they says there that the RMS Continuos Output Power is:

Vs=+/-35V,  RL=8 ohms   60 W min   70 W typical.
Vs=+/-31V,  RL=6 ohms   60 W min   70 W typical.
Vs=+/-29V,  RL=4 ohms   60 W min   70 W typical.

I dont understand fully something.  I have a 24+24/6A  tranny, and maked a power source with a rectifier bridge with 4 diodes (6A60), a 100nf ceramic cap in parallel with each of them, 4 electrolitic cap (4700/63v each, 3 for rail), and 2 100nf poliester cap (one for rail).   I guess that i ll get around 34V CC for each rail.  If i use this power source, i wont use a 4 ohms speaker with this tension?

I hope expresed clearly enough....