AB763 Amp

[Matthias]

I'm a recent addition to the forums so I hope this is the correct area to post my build pictures.

Over the course of the past few months I've been building a amp based off the hoffman ab763 board. My first idea was to make a super reverb. I wanted to make it a head so changing speakers would be easy. I love nearly all blues SRV, the 3 kings, ect. I first thought about a Weber kit, but decided to start from scratch, sourcing all the parts myself. I wanted better transformers and parts in general. I love the hoffman board, very tidy.

 Needless to say, this forum and all the info on the site really helped out. Big thanks to everyone! You're awesome.

Enjoy the pictures of my build, laugh if you must, it's my first built. I'm proud of it!

[Matthias]

Pictures continued

[Matthias]

Nearly finished, just need grill cloth, feet, and handles. Not sure I like how the cabs turned out, its just cheap pine and ceder with oil based polyurethane. However, it sounds awesome!

[Matthias]

My brothers point of view

[eleventeen]

With the possible exception of lead dress on the tone controls (which might induce some noise) I don't see anything at all ugly or "funny" about your build, it looks "super". Excellent job! Nice cab, too!

[TIMBO]

Hi Matthias, Welcome aboard.Very nice, with builds like that it will make us all  . By the way nice fur coat.Good luck  

[John]

Wow, I'm humbled at how well your first build turned out, it looks great! The only thing I'm laughing at is your brother's poster. 

[Rev D]

 Super clean looking build. Compared to my 18 watt marshall trem its factory clean. I got rid of all evidence of that amp and built a 18 watt lite IIb instead, still wasn't as clean as yours but didn't have 18 miles of wire running heather and yon all through a way to big solid state chassis donor. haha. Wasn't till I got to my 5e3 where I finally smartened up a little bit with the lead dress. Great job Man, heck I'd be proud to play that one!

Regards,

Don

[kagliostro]

Nice Amp 

Kagliostro

[Fresh_Start]

VERY nice execution for a first build! 

Of course you've got enough wire to go into a limited production run...

Cheers,

Chip

[HotBluePlates]

Excellent woodworking and build execution!

If that were only your 1st build of #50-60 that you'd made, maybe I'd consider laughing. I think it's remarkably well done myself.

[Matthias]

Thanks everyone!  

The build had it's moments that's for sure!

I had the hardest time figuring out why the bias voltage was too low(or too high relatively speaking to 0v)...replaced caps, diode and resisters in the bias control...twice. Turned out the diodes were only ~50v rating, low enough to not work but not low enough to completely burn out it seems, my meter said the diode was ok! I had plenty spare caps and resisters to fit the bill, but only two diodes. I stopped by crapshack for some beefy diodes and tada! I had bias voltage.

Lead dress! I defiantly will work on it, It needs work but I have been so revealed  that the amp is in working order that I've delayed. Hardly any noise or hum, even at full volume, but some. There is a very slight hum that does not change with volume - any ideas? I'll have to work on lead dress and poke around with a chop stick at any rate.

I do have to keep the reverb tank in the speaker cab, just too noisy with in the head cab(any ideas?)

[EL34]

Very nice... good job

Reverb tank outputs have to be as far away from transformers as possible since it's a very low level signal

I love your brothers cartoon!

[PRR]

> the cabs turned out, its just cheap pine

Where did you find the wormy stuff around the grill?

I have to rip old shipping-skids to find "character" like that.

(My kitchen counter is a 22" wide 4" thick slab from local old-growth pine. After some remodel I needed some trim behind it. I dug in the kindling pile to find something that didn't look too new or neat.)

Kudos to brother too. Give the dog a scratch.

[archaos]

Very nice job, congrats Matthias !

I love your brothers cartoon!

+ 1 : awesome cartoons too. 

[Matthias]

The strip of wood around the speaker grill is some nicer wood - Birdseyes Pine I think?? It was leftovers from years ago, a project my brother did. I just didn't want to buy another 12"x8ft board  . The overall warm look is from using oil based semi gloss polyurethane clear coat.

The OIL soaks into that pine(which is yellow in nature) and gives it a "warm look" to quote the can.

I also let the wood sit outside a few days in the sun - maybe that helped?

 If you don't like the yellowish or warm look, using a WATER based clear coat would help prevent yellowish coloration. However, I'm not a big fan of polyurethane - it has a gummy characteristic as far as hardness goes, very hard to polish to a shine...It was like rocket science to get a shine on a desk I made.