Howler - combo amplifier

[J M Fahey]

>>>¿Slow?<<< No way, you are doing fine. A "big" company with lots of people usually takes around a year to develop a new product, and keeps improving as it's out there, in the frightening real world, where all unexpected bugs appear.
Congratulations on a very fine job.
Juan Manuel Fahey.

[Mangas]

A little info on progress ...
Still working on the clean channel. I don't want it to sound "clinically clean", as the vast majority of solid state amps do, so it has to be tweaked very carefully. The sound tweaking is performed using my genuine 1965 Les Paul Pro Deluxe.



So far, everything slowly fits in its place. Sound is very opened and dynamic. The amp is starting to lose its clean tone when volume pot past 2 o'clock and cleans up well with the guitar's volume control (when cranked). But, there is a little "thing" that still bugs me and I am not completely satisfied with the result. On the verge of distortion, when light picking produces a clean tone and heavy picking produces a distorted tone, everything sounds cool (two and three strings riffs, full chords, single notes) except tones generated by extremely heavy picking high E and B strings in the high neck position. This is evident only when using a plectrum. Playing with fingers doesn't "show this phenomenon". It is not so evident and has nothing to do with sudden "transistor amp distortion", ghost notes, etc ... It just has no place in sound pattern by my criteria, period. I can easily get rid of it, but "standard ways" make sound less open and airy. So I had to modify some of the existing modules and build some new ones to solve the problem.



And "the battle" continues ...
I wish you all Merry Christmas (to those celebrating) and Happy New Year.   <3) <3) <3)

[joecool85]

Good work so far, also, LOVE the guitar!

[J M Fahey]

Impressive piece of Engineering.
I guess you must have full access to a well equipped factory or metalshop, that amp was not built in a log cabin in the woods.
I loved the "motherboard".
I always suggest everybody to get a piece of plywood or pine, mount there a Proto (or two) and screw solidly a piece of aluminum full of holes for jacks, pots and switches, but yours deserves a Nobel Prize.
Congratulations.

[phatt]

Hello Mangas,
                   First let me say very tidy work, quite stunning in fact.
Your efforts are certainly neater than  mine

Something does not sit right in my head with the first post pic, the bottom pic.
The mains input board has the mains cable *Earth wire* terminated on a PCB. Then I assume a thin copper track back to another terminal and then finally a lead to the chassis bolt.

I'm just wondering if this is safe practice?
From memory this would not pass Austrailian standards but other countries will have differing rules.

I personally would make a *Direct unbroken wire* to Chassis terminal from a mains cord.
In fact when I can I make sure the Earth wire is the longest so that in a worst case situation where the cord is yanked from the chassis the Earth wire is the *Last one to break* thereby minimising the risk of shock to the user.

It's a one in a million chance but that's just me.
Having said all that I probably still do things that more experienced folk would see as risky.
But hey that's what is good about other eyes looking at our work, there is often someone who has thought of something I may miss.

Cheers, Phil.

[Mangas]

Impressive piece of Engineering.
I loved the "motherboard".
I always suggest everybody to get a piece of plywood or pine, mount there a Proto (or two) and screw solidly a piece of aluminum full of holes for jacks, pots and switches, but yours deserves a Nobel Prize.
Congratulations.

Thank you J M, for your too kind words. You're making me blush. 

I guess you must have full access to a well equipped factory or metalshop, that amp was not built in a log cabin in the woods.

I wish that was true. Believe it or not, 70% of the amp was assembled on the floor of my study because the desk is not big enough for all of the instruments, modules, wires and cables. That creative disorder of mine is driving my wife crazy.  :grr
I have a few pals - one is good with metal, another is good with wood ... All in all, they are a bunch of crazy enthusiasts (like myself) ready to "meet my demands" at reasonable fee. What can I say... I am fortunate to know a couple of guys like that.

But hey that's what is good about other eyes looking at our work, there is often someone who has thought of something I may miss.

I couldn't agree more.

Something does not sit right in my head with the first post pic, the bottom pic. The mains input board has the mains cable *Earth wire* terminated on a PCB. Then I assume a thin copper track back to another terminal and then finally a lead to the chassis bolt. I'm just wondering if this is safe practice? From memory this would not pass Austrailian standards but other countries will have differing rules. I personally would make a *Direct unbroken wire* to Chassis terminal from a mains cord. In fact when I can I make sure the Earth wire is the longest so that in a worst case situation where the cord is yanked from the chassis the Earth wire is the *Last one to break* thereby minimising the risk of shock to the user.

And I am very glad that the fellow forumers pay that much attention to my posts.

First off all I would like to say that what you see here is not a final product, but the prototype. Only the PCBs have their final form. I'm surprised nobody has mentioned somewhat bizzare chassis construction. Initially my intention was to build something like 1970's Fender Champ - a little practice amp with Volume, Bass and Treble controls. So I bought 8" Jensen speaker, built appropriate cab and ... found out that I have Accutronics type 8 reverb tank spare. And it begun ...
Reverb? ... Why not?
Footswitchable? ... Why not?
Normal / Boost ... Why not?
Footswitchable? ..........
And there I was ... A zillion ideas running through my head, a little neat cabinet with sweet sounding speaker and ... a lack of space in the cabinet. Finally, I managed to tuck all in at the cost of chassis specific shape and component disposition.
The final product will have bigger cabinet, 10" (probably 12") speaker, chassis mounted male IEC main's socket and detachable AC power cord. Main's wiring cable (two layers of PVC insulation) will be mechanically fastened at both ends (Main's PCB (the pic previously posted) and Main's socket) inside the chassis. So, there is no way to "yank the cord" from the main's PCB and break "The Earth wire". Beside the fuse, there are the earth isolation circuit (10 Ohm resistor, 100nF capacitor, two antiparallel diodes) and metal oxide varistor as additional safety components. All capacitors are class X2.

Pretty safe ... I'd say.
     

[phatt]

Thanks for the details and pic Mangas, :tu:
You have obviously got it all sorted and should be a darn fine piece of well made equipment when it's finally done.
But it is all rather addictive and your wife probably wants to know if you will ever be finished,, LOL.
Phil.

[Brymus]

I must say.
This is probably the most impressive looking home built SS amp I have seen.
I am in awe  <3)
In fact it looks better and more "pro" than alot of the no-name brand SS I have seen for sale in stores and online.
Also...
Kudos for sharing,and not asking for help then declaring it "proprietary" knowledge.
Like so many seem to do in the DIY arena.

[Mangas]

Finally, the time for uploading some preliminary sound samples has come  xP xP xP . The clean channel is almost finished. Only a little "polishing" is needed considering a choice of active components and capacitor types (ceramic (np0, silver mica), polyester, polypropylene). Thanks for your patience. All comments are welcome.

A little info on clips :

Fender_1.zip (Fender_Clean.mp3) - Fender Stratocaster, neck and middle position pickups, clean sound (volume on 5, treble on 8, bass on 6, reverb on 5, middle boost off). Had to cut off intro to fit the file into 512kB. Sorry.

Fender_2.zip (Fender_Attenuated.mp3) - Fender Stratocaster, neck position pickup, amp fully cranked, guitar volume pot rolled back (volume on 10, treble on 6, bass on 6, reverb on 3, middle boost on).

Gibson_1.zip (Gibson_Clean.mp3) - Gibson Les Paul Pro Deluxe, both pickups, clean sound (volume on 4, treble on 6, bass on 6, reverb on 5, middle boost off).

Gibson_2.zip (Gibson_On the verge.mp3) - Gibson Les Paul Pro Deluxe, neck pickup, on the verge of distortion (volume on 7, treble on 7, bass on 6, reverb on 5, middle boost on).

Next stop ... The boost channel

[Mangas]

The rest of the files ...