Cheap 1 watt guitar amp kit?

Tim S

Tele-Afflicted
Gold Supporter
Joined
Oct 27, 2008
Posts
1,628
Location
Upstate NY
I’m guessing that building ^that^ is probably cheaper than buying a Tone King Gremlin (which proclaims the same SE BF/Tweed functionality).
 

printer2

Poster Extraordinaire
Joined
May 24, 2010
Posts
8,281
Location
Canada
I’m guessing that building ^that^ is probably cheaper than buying a Tone King Gremlin (which proclaims the same SE BF/Tweed functionality).
Well that is interesting. I was thinking of how to do the above circuit and it hit me that you can have a regular Champ with just one 12AX7 and a 12V6 and the BF and Tweed controls after the first stage and then mixed in before the second. I was not sure about the loading on the first stage so I thought a Mosfet follower after it would easily drive two without much interaction. In the Tone King manual I found this.

No. Function Type
V1 1st Gain Stage either Channel 1&2 12AX7
V2 2nd Stage C.F. Channel 1&2, Driver Stage 12AX7
V3 Output Tube KT

I never realized they had only a volume and tone control on the amp. Why would you not have a volume control for each channel? I wonder how they are using a Cathode Follower after the first stage, this seems to be saying that they are combining the signals before the CF, do they have the volume and tone control after, or volume before, tone after? I wish someone would do a gut shot and post a picture.

Anyway, the above schematic would probably go above $100 as the added cost of another 12AX7 along with the assorted parts. Also rather than a 12V6 a 6V6 will be double the cost. Mind you, when you were buying the parts I would buy a second 12V6 as a spare. That is why I drew uo the above schematic, you can use a 6V6 that you can get at any music store, the 12V6 you would have to send away for them. Looking at the Tone King, I guess you could use a Blackface tone stack in resistors rather than pots then have two volume controls and a tone control. It would shave off the cost of two pots, still think they would be worth the addition $5. Now looking at it another jack on the input would work well, the BF channel input to the Tweed jack switch. You could plug into the BF channel and the both channels would have the signal. Then plugging into the Tweed channel would break the switch and each channel would be separate.
 

Tim S

Tele-Afflicted
Gold Supporter
Joined
Oct 27, 2008
Posts
1,628
Location
Upstate NY
Well that is interesting. I was thinking of how to do the above circuit and it hit me that you can have a regular Champ with just one 12AX7 and a 12V6 and the BF and Tweed controls after the first stage and then mixed in before the second. I was not sure about the loading on the first stage so I thought a Mosfet follower after it would easily drive two without much interaction. In the Tone King manual I found this.

No. Function Type
V1 1st Gain Stage either Channel 1&2 12AX7
V2 2nd Stage C.F. Channel 1&2, Driver Stage 12AX7
V3 Output Tube KT

I never realized they had only a volume and tone control on the amp. Why would you not have a volume control for each channel? I wonder how they are using a Cathode Follower after the first stage, this seems to be saying that they are combining the signals before the CF, do they have the volume and tone control after, or volume before, tone after? I wish someone would do a gut shot and post a picture.

Anyway, the above schematic would probably go above $100 as the added cost of another 12AX7 along with the assorted parts. Also rather than a 12V6 a 6V6 will be double the cost. Mind you, when you were buying the parts I would buy a second 12V6 as a spare. That is why I drew uo the above schematic, you can use a 6V6 that you can get at any music store, the 12V6 you would have to send away for them. Looking at the Tone King, I guess you could use a Blackface tone stack in resistors rather than pots then have two volume controls and a tone control. It would shave off the cost of two pots, still think they would be worth the addition $5. Now looking at it another jack on the input would work well, the BF channel input to the Tweed jack switch. You could plug into the BF channel and the both channels would have the signal. Then plugging into the Tweed channel would break the switch and each channel would be separate.
FWIW, I don’t have a Gremlin, I have a Sky King. But I recall reading here that there’s a significant volume difference when switching pre-amps on the Gremlin. That has to be annoying in some situations (but if you use the Tweed side exclusively for leads, maybe that’s fine?)

You’ve got me curious about this. Thanks for the mental exercise.
 

printer2

Poster Extraordinaire
Joined
May 24, 2010
Posts
8,281
Location
Canada
FWIW, I don’t have a Gremlin, I have a Sky King. But I recall reading here that there’s a significant volume difference when switching pre-amps on the Gremlin. That has to be annoying in some situations (but if you use the Tweed side exclusively for leads, maybe that’s fine?)

You’ve got me curious about this. Thanks for the mental exercise.
The volume difference would be something of a feature if you want your leads louder. But with only one volume control you do not get to chose how much. The darn mental exercises, I go through them all the time. I find something curious and need to figure it out.

"I just looked at a sampling of 12AX7s including RCA, GE, Sylvania, Telefunken, Mullard, Westinghouse and a few Japanese rebrands.
They all consistently have pin 4 powering the filament for triode 1-2-3."

"So I figure the 1st section (pins 1,2,3) is heated by the heater connected between pins 4 & 9."

Just looked at a 12AT7 tube, the heaters are separate for each triode.
 

Randwulf

Tele-Meister
Joined
Oct 29, 2015
Posts
212
Location
ontario
Hi,
Is there a really low cost, simple tube amp kit in the 1-5 watt range (prefer 1 watt, but anything in that range is fine). I'd prefer to build a small head, and would like it simple enough that I would not need to buy a lot of tools I don't already have
Not looking for amp breakup, as I would just run pedals. Something 6L6GC based.
Is there anything like that available?
I have never built an amp before.
Thanks.
I think Trinity Amps in Brighton Ontario Canada offer a small 1 to 5 watt kit
 

keithb7

Poster Extraordinaire
Joined
Jan 9, 2010
Posts
5,246
Location
Western Canada
I agree with King, having spare salvaged components is key to building a tube amp on the cheap. Everything is getting expensive. Each manufacturer's costs are rising. They pass them along to the retailer. He passes it along to you. Transformers. Tube sockets. Circuit boards. Switches. Jacks. Capacitors. Tubes. The cabinet builder has to eat. The chassis builder has to eat. Lumber and tolex or tweed covering prices are rising. Then there is freight costs.

You assembling the amp, aside from the education and experience, does not save you much if any money. You can go find a 5W Epiphone Valve Jr head for cheaper than building your own tube amp from scratch. However, these are not going to be the quality you could build at home. If you choose to.




Saying this, I have built many tube amps. For the pleasure and satisfaction of it. It's a ton of fun.

I am not able to figure out how, but I think it would be cool to build a tube amp out of 12AU7 tubes. 3 cascading gain stages. Some type of circuit with a gain knob to pour the line signal from one 12AU7 into the next to get yet more gain. Then a nuclear switch to hit a 3rd 12AU7. Maybe a couple of different cathode cap values. Switchable to take the boiling over, over the top if wanted. One 12AU7 phase inverter. Then out to a couple 12Au7 power tubes. If you found an old tube organ you'd have enough 12Au7s to last the rest of your life time!
 
Last edited:

radiocaster

Poster Extraordinaire
Joined
Aug 18, 2015
Posts
9,743
Location
europe
This thread is an excellent collection of bad ideas.

First of all, a small tube amp for clean sounds. That's not what they're for.

Second, almost zero electronics experience.


I could recommend some kit, but it's likely to be another bad idea.

Other than that, the Wangs 5 watter can be pretty clean, that might work out and there's nothing to build. Some of the Hotone amps might do the job as well.
 

Skyhook

Tele-Afflicted
Joined
Aug 12, 2014
Posts
1,714
Location
Turku, Finland
Hi,
Is there a really low cost, simple tube amp kit in the 1-5 watt range (prefer 1 watt, but anything in that range is fine). I'd prefer to build a small head, and would like it simple enough that I would not need to buy a lot of tools I don't already have
Not looking for amp breakup, as I would just run pedals. Something 6L6GC based.
Is there anything like that available?
I have never built an amp before.
Thanks.

1) Buy a Marshall MS-2. They generally go for under 50 bucks.

2) Smash it with a hammer.

3) Put it back together.

BOOM! Instant 1W Amp -kit! :lol:
 

Guitarteach

Doctor of Teleocity
Joined
Aug 6, 2014
Posts
11,739
Location
The unfashionable end of the Western Spiral Arm
You want this.. Ampmaker WF-55 kit.

… can run a variety of 6V6, 6L6 and EL34 tubes. Mine has a 50’s RCA 6V6 and a 60’s Mullard.. through a 12” Celestion Blue.. tone perfection. Plenty loud and clean.

Excellent, easy to follow instructions and the vital testing guidance to keep safe.


i added a tone control too.. in notes, as well as variable negative feedback (like presence control)
 
Last edited:

printer2

Poster Extraordinaire
Joined
May 24, 2010
Posts
8,281
Location
Canada
I did a little experiment. Years ago I was a part of a $100 Challenge to design a tube amp for under $100. I think the chassis was not included, made a 12AQ5 (7 pin 6V6) Push Pull Harvard. I sourced most of the parts from one vendor as additional shipping charges account for real money even if it was not included in the $100. Did it again this time a single ended amp using a 12V6 but including chassis.

PDAszR3.png


Did not include the 12V laptop supply, I usually found them in thrift stores for $2-3. Probably add another $12 if you were to buy one new. The other thing about using a high voltage module is it is a lightweight amp and if you have a light cabinet (pine, weigh the wood in your hands, some pieces applicably lighter).

It was a dumb thing going through the exercise but I was curious.

https://www.tubesandmore.com/products/tagboard-300mm-x-56mm-2-x-28-tags $9.95

https://www.tubesandmore.com/products/vacuum-tube-12v6gt-tetrode-beam-power $6.90

https://www.tubesandmore.com/products/vacuum-tube-12ax7-ecc83-jj-electronics $13.25

https://www.tubesandmore.com/products/transformer-output-8-w-single-ended $15.50

https://www.tubesandmore.com/products/socket-belton-micalex-8-pin-octal-mip $3.50

https://www.tubesandmore.com/products/socket-belton-9-pin-miniature-top-mount $2.95

https://www.tubesandmore.com/products/14-jack-switchcraft-mono-shunt-tip $2.35 x2

https://www.tubesandmore.com/products/14-plug-switchcraft-cable-mount $3.15

https://www.tubesandmore.com/products/chassis-box-hammond-aluminum-8-x-4-x-2 $13.28

https://www.tubesandmore.com/products/receptacle-iec-c14-power-cord-3-prong $1.95

https://www.tubesandmore.com/products/fuse-holder-fender-3ag-type $2.50

https://www.tubesandmore.com/products/knob-chicken-head-set-screw-brass-inset $1.25 x 4


250k $1.55 x3 1M $1.55 x1

https://www.tubesandmore.com/products/capacitor-450v-axial-lead-electrolytic 22uF $2.20 x3

https://www.tubesandmore.com/products/power-jack-dc-panel-mount-55mm-external-21mm-internal $0.75

https://www.tubesandmore.com/products/switch-carling-mini-toggle-spdt-2-position-solder-lugs $2.75 x2

https://www.tubesandmore.com/products/resistors-2-watt-metal-oxide-power

470R $2.85
39R $2.85



1M $2.30
33k
75k
1.5k
4.7k
10k
47R
2.7k

https://www.tubesandmore.com/products/capacitor-500v-silver-mica-5 500pF $0.84


0.022 $0.46 x2
4.7n $0.60
0.082u $0.61
0.047u $0.74

https://www.tubesandmore.com/products/diode-general-purpose-rectifier-1a-1n400x 1N4007 $0.25 x2

https://www.tubesandmore.com/products/capacitor-illinois-50v-axial-lead-electrolytic 22uF $0.60 x 3

https://www.tubesandmore.com/products/wire-22-awg-stranded-core-pvc-600v-variety-pack $11.50

https://www.ebay.ca/itm/144357187611?hash=item219c5be01b:g:QScAAOSwroVhsdRT $6.01

$149.33

Only need one diode to protect against the wrong polarity voltage adapter applied. I was not thinking low voltage and selected a 1N4007, not going to bother with getting a proper one, will not change the cost much. The BF stack is worth the extra money as compared to a basic tone control, another $15 for it and the switch that gets you a more Marshall response. I probably should add that the HV module has an adjustable voltage, you could turn the amp down and get into the sub 1W range.
 
Last edited:




Top