Dreamlands
Active member
I'm still on the fence with the Spark. As appealing as it is, the lack of an f/x send/return and the smartphone app thing leave future me feeling unsettled.
Amp Suggestions
- Thread starter Robert
- Start date
Robert
Reverse Engineer
The only problem there is that for anything taller than about 7 inches I'll really need the controls to be on the front.
If it goes on the shelf under my bench I would have to do the limbo to get to them, if it goes on the shelf above my bench I'll need a stepladder to reach them.
I connected it up via USB and changed the speaker model to 2x12" (vs the default 1x12" on Clean), that made a tremendous difference. I'm still a bit undecided at the moment, but it'll work short term.
I hate to be so critical over a tiny practice amp.... I'm not planning on playing shows or recording a demo with the thing, but it's essentially being used as a piece of test equipment, and I have a rule about test equipment... If I can't trust it I don't use it. At this point it could be hard to determine if a loss of low end (or phase cancellation, or clipping, etc) is because of the amp, or an issue with the circuit I'm prototyping.
I'm going to keep playing around with it and see if I can become "familiar" with the sound enough to feel comfortable, if not, I'm going to either try a Princeton or find a way to make my Twin fit in the space I have. I know my Twin, I know what it should sound like.
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Well if you want really low watts, you could always roll your own: http://ronsound.com/index.php?main_page=product_info&products_id=882
Not sure how good it sounds - but it might be fun.
Not sure how good it sounds - but it might be fun.
Do you have an old "bookshelf" speaker or two to pair with a TPA3118 module? Probably more accurate reproduction of the actual audio from any pedals in development, although you certainly have enough options in amp emulation if you wanted something more like a guitar amp sound.
Chuck D. Bones
Circuit Wizard
Agree, it's a bitchen little amp.
Plan on replacing the 12AX7, mine got very noisy after a few weeks. The TONE pot works better as C250K. If you need it to go louder in a big room, plug in a 2 x 12 cabinet, no joke! I posted the schematic on TDPRI.
Chuck D. Bones
Circuit Wizard
Care to share a schematic?
cooder
Well-known member
It's really built point to point after the original 5F1 schematic that google will throw up with the addition of a three position bright switch which adds a 100pf and 250pf mica cap across vol pot, middle position is stock no cap. The two other additions are negative feedback switchable from 22K (stock) to 10K to none. The boost switch adds a 25uF or 1 uF cathode bypass cap on cathode of first stage or none in middle position (stock).
Also I chose 0.033 coupling caps which will let a bit more bass through, simply because I had them floating around and I like the smell of Russian paper in oil caps.
Schematic and 5F1 description here: https://robrobinette.com/How_Amps_Work.htm
Guts of my build:
Nostradoomus
Well-known member
If I didn’t get the Origin 5 this would have been my choice....with your mods of course.
I run mine into a 2x15 if I’m feeling ridiculous.
Chuck D. Bones
Circuit Wizard
Well done!It's really built point to point after the original 5F1 schematic that google will throw up with the addition of a three position bright switch which adds a 100pf and 250pf mica cap across vol pot, middle position is stock no cap. The two other additions are negative feedback switchable from 22K (stock) to 10K to none. The boost switch adds a 25uF or 1 uF cathode bypass cap on cathode of first stage or none in middle position (stock).
Also I chose 0.033 coupling caps which will let a bit more bass through, simply because I had them floating around and I like the smell of Russian paper in oil caps.
It's not just point-to-point, I see some "air circuits" in there. What a cute little output transformer.
Harry Klippton
Not Interested
I've been really tempted by the origin 5c lately but I'm worried I'll be overly disappointed by the 8" speaker
Nostradoomus
Well-known member
Luckily it’s easy to swap out/convert to a head/plug into something else. I built up a DeadendFX Terrahawk (clone of the Butcher Pedals Pistol Slapper...Rory Gallagher in a box) and I’m tempted to just install it into my amp because it sounds amazing now.
cooder
Well-known member
Yes that's why it sounds so open and airy, organic and gluten free....
The cute output transformer is indeed tiny and as said both PT and OT are from an old valve radio.
Also I wired it to use the much cheaper Russian 6N2P preamp tube which is very similar to 12AX7 except different heater wiring.
Nostradoomus
Well-known member
Free range circuitry!
Chuck D. Bones
Circuit Wizard
Ya know, I must have jinxed myself by talking up my Monoprice 5W amp because I went to go play thru it a little while ago and no sound! Turns out the NOS 12AX7A I had in there blew one of the filaments. Still, 50+ years of operation & storage is not bad for a vacuum tube.
benny_profane
Well-known member
I actually picked mine up from your recommendation and have since suggested it to others. Hope you get a new tube in there soon!
Looks like a cool little amp - same rough size as the Bugera? Has anyone played one of the Bugera's?
BurntFingers
Well-known member
Did you know if you take the first B off the logo you get twice as much gain?