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Messages - joecool85

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Plugging in mono 1/4" plug into stereo headphone jack expecting stereo plug?  That could cause shorts.

The Newcomer's Forum / Re: Busking Amp for Bass & Vocals
« on: October 19, 2021, 12:01:23 PM »
I just looked at the TDA2003 spec sheet, it looks like you would get 4 watts at 12 volts, not enough for bass in my opinion, but I am not an expert.
If you have the kit, build it and run your send/line out/ to effects output of your amp into it, and run the output to a separate cab and see what it sounds like.
Or get the signal from your stereo/phone/MP3 player and try it, see how loud the music sounds.
If its not enough the just get another amp module, like I mentioned before, the TPA3116D2 has 15 watts at 12v on the spec sheet at 4 ohm speaker.
You will not us a lot of extra power with a TPA3116D2 if you keep the volume down.
Class D power amps are very efficient and only use a bit more then what you use, if you use a 100w class D amp and only turn it up to 10Watt you will only use about 12-13 watts of power, at least that's my understanding.
Check the spec sheets of the power amp you are thinking off using and find the power rating for the voltage you intend to use, that's what I would do.
Class D amps don't need big heatsinks as well which saves money and weight.

This is correct.  One thing to note though is the TPA3116D2 is an SMD component and difficult to solder.  TPA3122D2N is a through-hole component and much easier to work with.  There are several kits available with this chip, or you could do something on your own.

The Newcomer's Forum / Re: Busking Amp for Bass & Vocals
« on: October 09, 2021, 07:12:49 PM »
Looks like a class D amp would be up your ally.  I've been eye-balling this circuit for a while:

Amplifier Discussion / Re: First attempt to do upgrade
« on: October 09, 2021, 07:10:13 PM »

      I posted this in wrong forum sorry for that
       Could someone move this to beginner forum


No need to move this post, we're pretty loose on what goes in which section - chill place around here.

For us to help you in any meaningful way, we're going to need some pictures of the inside of this little guy.  I've never seen anything quite like it, so not sure where to even start.  My guess is you would need to build a basic preamp to sit in front of this amp, then you would start to get more of a "guitar amp" sound from it.

The Newcomer's Forum / Re: Hello
« on: October 01, 2021, 09:29:08 AM »
I dont have any Videos but i ccould take some pictures..
Most of the Stuff never made it in an enclosure
There s actualy only one.
It s a DIY Kit called little Rebel. It s two lm386 as poweramp with two Watt output.
Everything else was never more then breadboarded. Not sure if you want to see that but here you are ;)
The Picture shows a Tube Preamp Stage, Lm317 voltage regulator and Lm1875 Preamp.
I cant photograph the other stuff because its off the board.
Right now i m working on something i found on different pages and want to try out:
Preamp is running but the Poweramp isnt doing what it should. I ll post some pictures and descripe the problem in a seperate Thread.
So long

Thanks for sharing!  In the future, please try to post pictures that are something more like 2000 or less pixels wide.  It makes it easier to view for most folks.

Amplifier Discussion / Re: Roland Jazz Chorus 50 troubleshooting
« on: September 17, 2021, 09:00:25 PM »
Hi, guys.

It's been a few years since my last visit, and I'm happy to see the forum thriving.

A few weeks ago I was lucky enough to catch a guy in the act of throwing a pristine looking 1981 Roland Jazz Chorus 50 in the dumpster. I managed to stop him, and brought the amp home with me. However, not all is well inside this thing. The JC-series is known for their clean sound. This one will break into some nasty sounding distortion, even when playing soft with weak single coils. If I turn the guitar volume down to almost zero it does not distort, so it does react to dynamics. Also, the chorus effect and the reverb is not working. The Vibrato works as it should. Plucking the springs in the reverb pan comes thru loud and clear. All other controls seem to do what they are supposed to to.

The amp uses the same circuit as described in the second half of the service manual found here :

Here is a little video of the amp, showing the distorted sound.

There is no sign of bad solder joints, burnt components or bulging caps. I will recap this thing, but I want it up and running first. I don't think the problems are caused by gone electrolytic caps.
As far as I can see from the schematic, there is no logic in that both the reverb and chorus not working. Can anybody take a look at the schematic and help me with where I should start troubleshooting?

Any update on this amp?  Curious if you got it sorted.

Also, welcome back!

The Newcomer's Forum / Re: Hello
« on: September 17, 2021, 08:58:03 PM »
Welcome aboard!  I'd love to see pictures or video of some of your past projects!

The Newcomer's Forum / Re: Which replacement power cord?
« on: August 17, 2021, 07:12:17 PM »
That'll work well. Actually, any IEC power cables would work equally well for home and information products. Always use cords with a wire gauge of 0.75mm2 or greater(I dunno how much AWGs it equals to ... In my country, we use squared millimeters instead of AWGs to measure wire gauge ) to ensure an abundant supply of current and to eliminate risks of fire.

0.75mm2 is 18 gauge.  I wouldn't use anything smaller than this either.  At the length most power cables are (3-6' or 1-2M), they can push 15 amps very safely which gives 1,800w at 120v - way more than most of us would ever need!

Honey Amp / Re: Thoughts on my new Honey Amp
« on: August 05, 2021, 03:48:15 PM »
Hi there, I am interested in the Honey Amp kit. Where can I purchase please?

PM Sent.

Honey Amp / Re: Thoughts on my new Honey Amp
« on: August 02, 2021, 11:41:07 AM »
Hi there, I am interested in the Honey Amp kit. Where can I purchase please?


I'll be adding a web store soon to the site so you can purchase there.  If you'd like one sooner than that, please PM me and we can do a direct sale.

Honey Amp / Re: Power supply suggestions
« on: July 31, 2021, 09:14:30 PM »
Worrrd, I think I figured it out.

Much Appreciations!

Glad to hear it!

Honey Amp / Re: Thoughts on my new Honey Amp
« on: July 31, 2021, 09:13:33 PM »
" No power switch, but I can understand the omission, since this is supposed to be highly customizable. I have to pop the battery connectors to power down, but my enclosure choice makes that easy enough"

You could try a 3 prong switching jack that disconnects the battery ground when no cord is inserted.

Like pedals use.

Or just wire a switch inline with the battery - that's what I do.  I'm not a fan of onboard power switching, even when it is for a battery amp.

Regarding power output, it is an LM386 so it's about as loud as I could get it.  If you need more headphone volume, try using a lower resistance value for R10.  If you use 10 ohm it should just about blow your ear drums with any normal headphones - mine certainly did!

I'm planning another battery based kit, probably power amp only.  This one would be based on the PAM8302 which gives 2.5w and runs on a really low voltage of 5v nominal.  I've been playing with the board from Adafruit and it's significantly louder than any LM386 circuit I've used.

Amplifier Discussion / Re: My K-20X
« on: July 21, 2021, 03:13:16 PM »
That solid state amp does not require a load, you can simply turn off the speaker with a switch.

What I would do is connect the line out 10k resistor to the phones jack tip connection instead of the speaker.  Now the line out works when you are on speaker or when on phones.  Now the phones still work, but you can use the phones jack to kill the speaker.   Just plug an unwired plug into the phones jack, and that opens the speaker connection.But a switch works fine too.

Enzo, that's a pretty slick idea! I'm not going to re-wire mine since I rarely use the line out now anyway, but if I ever did another I would probably do it this way.

Honey Amp / Re: Power supply suggestions
« on: July 20, 2021, 10:26:25 AM »
Right on.

It's these details in certain facets of life, that somehow tend to escape me....

I just wasn't sure if there may have been something pre-designated on the board, for executing such a mod/addition.

Thank you!

Nothing on-board for this, just ground and positive input voltage.  Like Phil said, you would need to do this offboard like most pedals.

The Suhr Discovery Analog Delay has been released.  It looks to be an absolute beast of an analog device: built with old-school bucket-brigade IC tech, can store up to 127 presets, 17-2000ms delay range with digital readout, tap tempo input, multiple division modes (1/3, 1/4, 1/8, 1/16), and an array of controls.  Plus it is built here in the USA and looks to be made of sheet steel stamped into an approximation of a 1/32 scale Sherman tank.

This looks to be a very professional piece of kit, and comes with an appropriate price tag coming in with an MSRP of $549 USD.

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