I, personally, have not.  However, I've heard great things about them in other forums.  They're certainly not as awesome as Scumbacks or Webers but they supposedly hold their own, and are much better than your average stock speakers coming from China.

I love this thread and am super jealous that you got this amp for $40!!! 

I have a feeling that - with a proper distortion pedal - you can get crushing metal tones out of this \m/  Have you tried?  Regardless, I think it's time for some soundclips of this beast  :tu:

GREAT NEWS!

Finally, Damon and I were able to make time to sit down and determine what parts need to be ordered.  Soon, we will have the parts to begin constructing the protoboard of the preamp!

I'm so excited because now - in the foreseeable future - there will actually be something tangible/physical to show for all my work 

I will be sure to post updates as things progress  :tu:

Damon's website is marsynth.com/

Oops!   

Great news!

I recently was connected with a guy named Damon Mar who should be able to help me get a prototype of my amp going!  He's a musician, is about to receive his Masters in Engineering, and is also an entrepreneur.  He builds pedals that can be used with synthesizers, as well as guitars and they seem pretty cool.  He makes stuff more for people who like to make ambient-type noise, but I told him that I could definitely see metal bands (more like black/experimental metal) experimenting with his stuff.  Check out his website if you're interested: http://marsyth.com

We met for about 2.5 hours last Thursday and I told him all about the design and he says it's definitely something he can do.  Also, because he makes foot pedals and get stuff wholesale, I'll be able to get a deal on the parts.  Hopefully by next Thursday, he'll have an idea of most of the parts I'll need to buy.  After that, the plan is to make a protoboard with lots of sockets so we can swap out parts.

The best part is that he has an oscilloscope – that will be fun to use when we're measuring/messing with sound waves.

I'll be sure to keep this thread updated as the amp progresses.  When the amp starts making noise, would everyone like to see YouTube videos and listen to soundclips?

Sorry it's taken so long to update this page but things have not been going so well. To make a long story short, the guy I hired to build the amp didn't work out.  After repeated visits and discussions with this builder, I had to file claim with my credit card (I'm SO glad I didn't pay in cash).  The waiting period is over and the money is mine again, which is why I'm now just starting to continue with this thread.

As for my continuing search, I've gotten some "bids" where people have said they would charge me $800/hr for the design, which I can't afford (and personally, I think the quote was that high just because they didn't want to do it).

I suppose I could always try Craigslist.  If I could get someone just to draw up the schematic of the design, I'm sure I could find someone who could build it on the cheap, and then I could just tweak it. 

I've thought about just modifying an amp I already like to my specs.  This would be a chore (especially since I have limited knowledge of electronics) but it may be necessary.

I've already put so much time into this I think it would be ridiculous to just let it go.  Does anyone know how/who I could contact? Does anyone have any ideas?

That's so strange that the TDA's were designed that way.  I know they were originally meant for stereos, TV's, etc (and not for guitar amplifiers) but still it seems, from the way you describe it, that it would be hard to use the TDA's regardless. 

I wonder why Marshall decided to use them?  I bet they probably just got a deal on a huge batch and said "f!!* it - let's make some money" 

That's nuts about the TDA's - I had no idea    I have a feeling we'll be going with the LM's unless the TDA's sound a million times better  :tu:

Quote from: DJPhil on September 02, 2010, 11:58:07 PM
I love the smell of new parts.

Somehow I totally missed this thread earlier. If you ever want to talk tech stuff and happen to be up in Omaha let me know. Not too many folks around here seem to be into electronics.

Keep us posted, I'm slowly working on a 3886 build here too, though I'm only after about 40W.

Me too  :tu:

Yeah man I'll totally hit you up if I'm ever up that way - thanks for the offer 

A big day has arrived!

Just thought I'd let everyone know that the LM3886T's and TDA7293's came in the mail.  Due to the overwhelming amount of recommendations we will most likely be using the LM3886T's, but we decided to buy some TDA7293's just for the fun of it  :tu:

Here are the LM3886T's:



Here is one of the TDA7293's:


Tom and I have decided on a small simple circuit to use for a mini-prototype of the amp (basically, we will be building a practice amp version of the beast).  Hopefully, we will be blowing stuff up within the next few weeks!   

Hello Everyone!

Sorry - I know it's been a while.  Unfortunately, since Tom and I are very busy making money so we can eat and pay rent, we do not have the ability to devote 100% of our time to this lol

To tide everyone over, I decided to post some pics of when I visited Tom's place.  I was unable to get any good pics of the outside so I may take some when I visit this week.  Apparently, this used to be THE place to party back in the 80's here in Lawrence, Kansas but (unfortunately) I didn't take pics of the entire place - just Tom's work space.  Seriously though - this place has a fucking balcony and everything \m/


This was my first view when I came down the stairs   


The pool table.
Whoever can find Tom's leg first gets a prize!   :tu:






The bar.






Tom's desk.




Tom fixes keyboards for people, and it is also his main instrument, so he has a lot of them hanging around.


Cigarettes, PCB, schematics, calculations I don't understand, and a subtext of METAL \m/

Some people would be alarmed if their technician's workspace looked like the preceding pics, but not me.  This is because, if it wasn't for the fact that I have a small apartment as well as a roommate, my place would look exactly like this too 

I will be meeting with Tom later this week and he will be showing me some IC chips, as well as a power transformer, that we will possibly be using. 

Don't despair - more updates should be coming shortly!

Quote from: phatt on July 08, 2010, 09:07:37 AM
Hi mgcasella,
                You may need to clarify the 150Watts? (Headscratch)
If that's what you expect to get from an LM3886T ,,then I have bad news as the best is about 50W @8R.

That said it is a stunning little chip and well suited for guitar in my recent findings.

I'm Having an absolute ball working with this little throw away.

See here:
http://www.ssguitar.com/index.php?topic=1672.0

Contains an LM3886T running from 36-0-36 VDC Rails.

I have not updated the progress as there has been a distinct lack of replies but if you wish I'll post the schematic of PowerAmp circuit and little Preamp I hooked up.

I only wanted to utilise a 2 knob preamp as all my fancy stuff is done via outboard preamps so I only need simple control over the poweramp chip section.

The wacky thing is it does a wonderful compression job of guitar signals  and I'm still looking into why that may be so but for the moment I'm having so much fun playing it I don't wish to pull it apart.

From what I've found so far;
If you want all clean power at 50Watts then don't bother with the LM3886 as it distorts when driven.  which is exactly what I wanted. A cheap little amp that breaks up nice,,,
I'm chuffed. <3)
Cheers Phil.
Edit: I should add it's friggin loud when you plug into a 15 speaker

Thanks for the info :tu:  As far as the 150 watts is concerned, since I'm not the engineer building this, I'm not quite sure how to answer your question    However, I'm sure Tom (the tech) will know.  Whether he'll have time to respond, however, that's another matter 

BTW even though I don't understand the technicalities behind your project I'm definitely going to check out your thread  :tu:

It's been a while - this I know   but we (Tom and I) are waiting on some stuff to come in the mail. For the purpose of experimentation we are going to be trying two different chips (TDA7293 and LM3886T) in the power section. By this, I mean we are going to try the TDA7293's in the amp first to see how they sound, and then see how the LM3886T's sound.

If anyone knows anything about these chips that we should know (that we wouldn't get from a simple Google search), and has an opinion on them, please speak up. Also, don't worry, there will be plenty of ventilation/airflow/heat-sinks as Tom said these things can get pretty hot  :trouble

BTW the amp is now officially planned to put out 150 watts.

PS: If anyone has a good schematic of the Mosvalve MV-962 please send it to me because Tom wants it  :tu:

Quote from: J M Fahey on June 15, 2010, 11:29:54 AM
Thanks, MG, it's very kind of you posting it here.

No prob - you're very welcome!   :tu:

I am in Lawrence, Kansas   <3)

Here are the features so far:
-The design is based off a few common favorite ss amps that are specifically good for METAL (such as the Ampeg VH-140C [LOOSELY, that is]) plus the addition of extra controls and features (such as a "Depth/Resonance knob)
-100 watts
-----I was skeptical about just having 100 watts but Tom assured me he knew what he was doing.  He also said if I wasn't completely satisfied then we would tweak it until I was or I didn't have to pay him  :tu:
-Two inputs:  High gain and Low gain
-Two channels:  Clean, and Distorted (plus a Boost switch for the second channel for soloing, getting even more gain if you are doing straight up grindcore/noise, etc).
-Two output jacks with a choice of 4, 8, or 16 ohms
-Direct line out
-Effects loop
-Reverb (because everyone knows you sometimes just need a little bit of it
-Master volume

My goal is to make a high quality amp that is specifically for METAL \m/ (and that includes all sub-genres).

If anyone can think of any other "must-have" features then please let me know!  This is still in the design stage so there is still time to include them.