Ptownkid

Small portable, really portable practice amp
« on: November 01, 2005, 08:54:27 AM »
Looking or info on a solid state amp build, something small like a pig nose.

Any leads?


Rochey

Small portable, really portable practice amp
« Reply #1 on: November 01, 2005, 09:19:28 AM »
do a google for "Gainclone"
Expat Audio Home: http://www.expataudio.com

Small portable, really portable practice amp
« Reply #2 on: November 01, 2005, 01:19:01 PM »
the ruby over at www.diystompboxes.com is a fun and small little amp that can drive a 4 twelve cab.

good luck.

Ptownkid

Small portable, really portable practice amp
« Reply #3 on: November 01, 2005, 04:32:41 PM »
ok, so i checked out the rubt, but there's one thing I don't understand.....

http://www.runoffgroove.com/ruby.html

it shows there being a speaker present, but don't I need to know what watt and resitance the speaker needs to be?

kiira

Small portable, really portable practice amp
« Reply #4 on: November 01, 2005, 07:38:49 PM »
foo... it's aguitar amp so it has to have tubes.

http://annex.ax84.com/media/ax84_m276.gif

vibrolax

Small portable, really portable practice amp
« Reply #5 on: November 01, 2005, 09:14:28 PM »
Here's one of my guitar mini-amps (all tubes of course), and a bit simpler than the AX84 firefly referenced in the previous post.  Built into a PC power supply box:

Link

Schematic and detailed pics provided.

Jon

NewYorkDave

Small portable, really portable practice amp
« Reply #6 on: November 01, 2005, 09:17:14 PM »
...and here's a couple of small guitar amps from yours truly...

Solid-State
Tube

PRR

Small portable, really portable practice amp
« Reply #7 on: November 01, 2005, 10:30:57 PM »
> it shows there being a speaker present, but don't I need to know what watt and resitance the speaker needs to be?

Bah. Only wimps and technicians worry about "power rating" and "impedance". Real players just play. If something smokes, it was no darn good to begin with, right?

Speaking as a wimp and technician: I think a LM386 on 9V supply is good for about a half-Watt at most. With a solid 9V supply, maybe a whole Watt of gross distortion, on a 9V battery you won't be able to hold even the half-Watt long enough to melt a small speaker. Yes, if you really shop around, you can find "loudspeakers" that can be melted with 1/10 Watt; if you just grab a kitchen radio from the second-hand thrift-shop, its speaker will take everything the LM386 can dish out.

Impedance? Well, the LM386 will distort more at medium level with 4Ω than with 16Ω, but at full-blast it is all about the same.

Oh: a half or whole Watt may seem like it would be lame next to your 80W big-amp, but you can make a heck of a racket with a part-Watt and a good speaker.

Oh: put this little amp into a twin-twelve cabinet and it will make a very gutsy racket yet not at such volume that you wake people two streets over. That does not fit your definition of "portable", I suppose, but do try it with a big speaker. A fairly large speaker, like a screaming-Six, in a large but lightweight (corrugated cardboard, or 3mm plywood) box will make the most of a minimal amplifier.

> it's a guitar amp so it has to have tubes.

Agree, but: tubes are such power-pigs that battery or ultra-compact construction just isn't happening. When location is more important than tone, you can make a nice noise with an FET/386 amp and a 9V battery, and play anywhere.

kungfugeek

Small portable, really portable practice amp
« Reply #8 on: November 01, 2005, 11:59:58 PM »
Anyone know of any circuits similar to this?  http://zvexamps.com/ampsound.html  I think it sounds fantastic.  I am not looking to clone the Z, but achive a similar sound, with similar flexibility.  Would be used strickly for recording, so 1/2 watt is ideal.

PRR

Small portable, really portable practice amp
« Reply #9 on: November 02, 2005, 01:58:54 AM »
> I think it sounds fantastic.

Many amps can, when played "through a 1970 Orange 4X12 cabinet with 4 original Celestion greenbacks."

What strange tubes. They must have got a Good Deal on a case of those. Offhand, I doubt you want a "faithful clone" because the tubes are probably not the "sound", it is the way they are used, and those tubes are just strange. Probably missile spares.

Use the kitchen-radio tubes. 60FX5 is a killer one-watt, you could run 75-90V on the plate for part-watt use. 50C5 were used by the millions, and a 50C5+12AX7 can be fed 62V plate and heater and make a half-watt. 50EH5, 50FK5, 50HK6 are similar (minor differences in ratings, but mostly I bet the radio-maker wanted a monopoly on replacements...). 50L6GT is the classic Octal of the tribe, runs a lot like 50C5 except can take more voltage, and can be stoked up to nearly 4 Watts output. I think all these (except 60FX5) are 0.15A heaters so you can stick a 12AX7, 12AT7, 12AU7, or 12SN7 12SL7 or even 12SJ7 in front for gain. Tinker the tone-stack, gain structure, R-C coupling networks for best guitar action. After 50 years, the Fender front-end is still the foolproof way to start.


Small portable, really portable practice amp
« Reply #10 on: November 02, 2005, 02:56:51 PM »
Quote from: "Ptownkid"
ok, so i checked out the rubt, but there's one thing I don't understand.....

http://www.runoffgroove.com/ruby.html

it shows there being a speaker present, but don't I need to know what watt and resitance the speaker needs to be?


ive built a few of the ruby's and i can tell you that they sound great!  if you want something a little more powerful, the ruby mkII is a 1 watt version using two 386's ....

one time i plugged one into a genz benz 2 12 cabinet...and it was plenty loud enough, and there is something about the way it overdrives that sounds really gutsy and nice.

the parts are easy to get a hold of....you can get them at ratshack if you'd like....

also - someone inquired about a smaller tube amp like zvex's....  there is the "sopht" amp that's pretty small and sounds really good...cant remember the maker's name, but i want to say it was "johan."  full diy information on his site....google it.

see ya-

casey

Small portable, really portable practice amp
« Reply #11 on: November 02, 2005, 02:58:47 PM »
here is an example of a ruby someone built:


kiira

Small portable, really portable practice amp
« Reply #12 on: November 02, 2005, 03:59:35 PM »
Quote from: "Lo-Fi"
here is an example of a ruby someone built:



gah that is soooo cute I wanna build one but I can't stand to listen to anything through less than a 12" cabinet... and I like a 4x12 or stack best. There is just something about that "whump" you get with a closed back 4x12 or stack. Ok I'm a dinasour from the 80s for liking my V4 and jcm800.

Kiira

CJ

Small portable, really portable practice amp
« Reply #13 on: November 02, 2005, 04:24:37 PM »
Lucky homeowners.
 :cool:
If I can't fix it, I can fix it so nobody else can!
Frank's Tube Page: www.mif.pg.gda.pl/homepages/frank/vs.html
Guitar Amps: http://bmamps.com/Tech_sch.html

bcarso

Small portable, really portable practice amp
« Reply #14 on: November 02, 2005, 06:09:32 PM »
Quote from: "kiira"
Quote from: "Lo-Fi"
here is an example of a ruby someone built:



gah that is soooo cute I wanna build one but I can't stand to listen to anything through less than a 12" cabinet... and I like a 4x12 or stack best. There is just something about that "whump" you get with a closed back 4x12 or stack. Ok I'm a dinasour from the 80s for liking my V4 and jcm800.

Kiira


But Kiira, wouldn't that be a cool thing to carry into a posh retaurant as if it were a handbag?

Small portable, really portable practice amp
« Reply #15 on: November 03, 2005, 09:28:57 AM »
Quote from: "kiira"
Quote from: "Lo-Fi"
here is an example of a ruby someone built:



gah that is soooo cute I wanna build one but I can't stand to listen to anything through less than a 12" cabinet... and I like a 4x12 or stack best. There is just something about that "whump" you get with a closed back 4x12 or stack. Ok I'm a dinasour from the 80s for liking my V4 and jcm800.

Kiira


you could easily put a switch jack on it so that you could plug a cabinet into it.  or you could just build it as a head and put it into any cab you'd like.

Ptownkid

Small portable, really portable practice amp
« Reply #16 on: November 03, 2005, 10:34:52 PM »
on the schemo it list the pots as being1k-b and 10k-b, what does that mean?

Small portable, really portable practice amp
« Reply #17 on: November 03, 2005, 11:00:59 PM »
Linear taper.

Ptownkid

Small portable, really portable practice amp
« Reply #18 on: November 11, 2005, 12:29:22 PM »
Ok, so i built two of these guys, and all I get out of them is distortion, or a lot of distortion, there's no cleanish tone at all.

Also, when you pluck a note, it hardly sustains at all and then quickly crackles off into nothingness in the blink of an ye, it's like it's got a gate.

Mbira

Small portable, really portable practice amp
« Reply #19 on: November 11, 2005, 12:57:30 PM »
Clean tone is a result of lots of headroom (extra power).  You probably won't get much clean headroom from one of those.
Joel Laviolette

Rattletree   |  https://www.rattletree.com
The Rattletree School of Marimba | https://www.learnmarimba.com


 

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