New Build Complete

[ChrisM]

This amp started about a year and a half ago. It's my first full build/design. The idea was to have a small little head (PR size chassis and cab) that covered lots of ground. The amp is 50W PP fixed bias. Clean and overdrive channel with a great reverb circuit thrown in too. The clean is like a mix between a BF Fender and a Dumble, the OD is an Dumble ODS with some tweaks here and there. Overall I think it sounds great!

The amp was actually done at the end of last summer. After finishing school this April I had some time to get back to it. Worked out some bugs and did some tone tweaking. Really when the amp started up the tone was ok but nothing special at all. The longest part was getting the tone dialed in to my liking. Spent the last couple months listening and tweaking. Finally yesterday I added some more NFB which did the trick for the last tone issue I was addressing. So now it is done!

[IMG:701:1023]http://img.photobucket.com/albums/v610/ ... /Front.jpg[/img]

[IMG:666:1023]http://img.photobucket.com/albums/v610/ ... Front2.jpg[/img]

[IMG:919:1023]http://img.photobucket.com/albums/v610/ ... utside.jpg[/img]

[IMG:811:1023]http://img.photobucket.com/albums/v610/ ... gut1-1.jpg[/img]

[IMG:764:1023]http://img.photobucket.com/albums/v610/ ... s/gut3.jpg[/img]

[IMG:764:1023]http://img.photobucket.com/albums/v610/ ... gut2-1.jpg[/img]

[IMG:764:1023]http://img.photobucket.com/albums/v610/ ... s/gut5.jpg[/img]

[IMG:764:1023]http://img.photobucket.com/albums/v610/ ... s/gut4.jpg[/img]



Tone is amazing! I dialed it in perfectly for my strat. All pickup positions sound fantastic (something I haven't really found on any other amp, usually don't use bridge). Cleans are very full and complex with real popping bass and mids, very tight. Nice clear highs without being to in your face. Good bit of compression and feel to this channel.

Overdrive is great, really rips, gotta record it. 3 way voicing switch adds many tones and makes the OD quite versatile.

Reverb is ideal for me, not too in your face and intense as an old BF Fender. More mid emphasize in the reverb than the typical high influence of a BF Fender.

Lots of other neat switches and features...Class A switch and Mid Boost, Deep, Hi/Lo gain switches. O and adding the FX loop buffer, really like that tone wise. The FX loop buffer is switchable.


Circuitry has changed a bunch since original schems. I can post later if interested...

[selloutrr]

Congratulations! beautiful build

[MysteryFever]

Your workmanship looks excellent! Very tidy for such a crowded space. I too have just finished my first build which took me a couple months so I know how great it feels. Since this is your first, may I ask how you learned to build your own amp? Do you have any background in electronics?

[ChrisM]

Thanks guys!

This wasn't my first build, sorry that wasn't clear. Was my first attempt at designing something from scratch then building it. I've built dozens of amps before this one so I had some experience you could say. But ya I'm an electrical engineering student so I do know a little bit about electronics

[Chris333]

Looks great! Time to show it off with some clips!

[statorvane]

But ya I'm an electrical engineering student so I do know a little bit about electronics

You obviously know something about head and cab construction too! Very nice. What speaker(s)?

[martin manning]

Looks really cool, Chris! Great job packing all that stuff in there. I'd love to see a schematic if you are ok with sharing it.

[ampmike]

Nice Chris,I think it is great you are studying for a degree in electrical engineering,Its to late for me at fifty with 5 college students of my own.But if you have a passion for amp building and get a degree I cant think of a better place to be,Good Luck Bro,Beautiful amp,Mikey

[Structo]

Neat and tidy build Chris.

Are using the heater supply to power the relays?

What do you think allows a Strat to work well with this amp?

[ChrisM]

Thanks!

Tom there is actually a small 12V transformer in there. You can see it in the 5th pic. The wires from it are purple and yellow and run along with the heaters, they are zip tied to the heaters.


Someone asked me about the strat thing on another forum...

100K/1K5 through out. The lower plate loads play better with single coils. Dumble used that combo for a few amps that were specifically tuned for strats. Tried the high plate scheme and didn't like.

Strat tone I'm looking for something with tight bass with lots of punch. I hate amps that fart out on the neck pup. Needs big lower mids that really kick. Not so much emphasize on the highs. Any good strat will have enough nice highs and clarity on it's own. So I like them not super piercing and bright I'd say but still chimey and clear. A good bit of compression and touch sensitivity is always good too.

CF driven TS, 25K slope, 50nF mid, 50K mid pot, 20nF bass, 500pF treble with option of another 2nF in parallel. About 200V on the clean tube plates bit more on OD. Component selection.... Bit higher presence cap than most amps so the control is affecting the mid-high frequencies instead of the super high frequencies and the overtones. No one real drastic tone shaping area, just small tweaks here and there to get to the end result.

I think if you can make a strat sound good through an amp all the other guitars will fall in right along side and sound great too!


Schem for those interested...

[IMG:160:121]http://img.photobucket.com/albums/v610/kurtlives/th_CM-501.jpg[/img]

[IMG:160:121]http://img.photobucket.com/albums/v610/kurtlives/th_CM-502.jpg[/img]

[David Root]

Nice work Chris! I'll have to check out my #124 and my '70s ODS with a Strat. My Bloozman is high plate and sounds great with my LP.

[Zippy]

Gotta ask...

What difference do you hear/feel regarding the SS/tube rectifier?

Nice assortment of bells and whistles - Would you use them all in another build or is it more of a test platform?

Cheers!

[M Fowler]

Very nice amp build great detail in there

Mark

[Structo]

Chris,
Can you describe what the 220nf film caps in parallel with the 5uf electrolytic cathode caps do for the tone?

[ChrisM]

Gotta ask...

What difference do you hear/feel regarding the SS/tube rectifier?

Nice assortment of bells and whistles - Would you use them all in another build or is it more of a test platform?

Cheers!

Bit "browner" sounding with the tube, tad more compression and it sags a bit. Kinda cool variation. The On-Off-On switch also functions as a standby switch in the middle position so that's an added bonus.

Chris,
Can you describe what the 220nf film caps in parallel with the 5uf electrolytic cathode caps do for the tone?

Bit tighter clearer tone. Really helped with the tightness and attack on the low notes with the strat. This technique is common in hifi designs.