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Messages - joecool85

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Amplifier Discussion / Re: Thunderfunk with Dead Power Amp Board
« on: May 04, 2021, 11:50:47 AM »
Like most of these modules, the output is balanced. That means you can't ground one side, and you shouldn't use phone type plugs because there will be dangerous Voltages on the metal shells.

There is no good way to drop Voltages to what you need. You can burn several hundred watts via analog means, or build a switching regulator :(

Good points, and all the more reason to not use 1/4" jacks for speaker connections.  Time to use Speakon connectors.  It's been 25+ years, time for the industry to transition!

Regarding the voltages, you could use a DC/DC converter, but honestly I would just build out a new PSU for the power amp.  Leave the existing for the preamp if you'd like though.

I just looked at the datasheet you shared.  The +/-12v is for input voltage, IE signal.  Your preamp will provide that without issue I would guess.  You do need about 75v DC for the PSU though.  Looking at Parts Express, it seems that the board you linked is for use only to add on to another "ICE" board.  They recommend using this one with it's built in PSU for $312 USD:

Amplifier Discussion / Re: Chipamp kit LM1875 PDF?
« on: May 04, 2021, 11:44:45 AM »
Hey everyone. I was a member here way back when this forum began and was lucky enough to receive a couple of kits from Brian and this site. The LM3886 and the stereo LM1875.

I assembled the LM3886 kit but never got around to testing it because I couldn't afford the transformer and never assembled the LM1875 kit. Found them the other day and would love to finish them up. The LM3886 I reversed engineered it but would still like to check. The LM1875 I have no reference for.

If anybody has the PDF of the instructions that isn't a dead link I would much appreciate it.


Here you go:

Schematics and Layouts / schematics and manuals
« on: May 04, 2021, 11:44:22 AM »
I've had a few people ask about these so I figured I would share them.  Attached are the manuals (with schematics) for the LM1875 and LM3886 kits BrianGT sold at for a long time.

Honey Amp / Re: Got my kit!
« on: May 03, 2021, 09:07:52 PM »
I checked my box and it does look like I'm missing the sticker as well. I'll message you on Kickstarter. Thanks!

Sounds good, I'll get a sticker out to you.  Enjoy the kit!

Honey Amp / Re: Got my kit!
« on: May 03, 2021, 09:07:11 PM »
I received mine today, and the box was smashed almost flat, split open on both ends, and had stickers that said "RECEIVED DAMAGED".  Apparently the only thing lost were any stickers, since I checked all components and they were all accounted for.  I would like a sticker!

I did not understand the note on the schematic that reads "For gain circuit, do not populate R0 and C0".

Phil from gorgeous Young Harris, Georgia, USA

The gain circuit is the standard circuit.  You can use the modifications listed in the notes to have a buffer in front rather than a gain circuit.  I think I may take these notes off the schematic to avoid confusion...though I do want to say something about R0 and C0 so folks know they can leave them empty for a stock config.  I'll come up with something.

Regarding the sticker, I'll get it sent out to you.  Glad the damaged box still had everything in it!

Honey Amp / Re: Got my kit!
« on: May 03, 2021, 09:20:00 AM »
Glad to hear it came in okay!  I forgot to put stickers in the first few, if yours is one of them and you want a sticker, let me know and I'll mail it out separate.

TC Electronic has released their new Skysurfer Mini Reverb, a small footprint version of their original Skysurfer.  It packs all the same functionality, but with smaller switches and knobs and much less wasted space.  For only $50 USD, this one sounds like a keeper!

Amplifier Discussion / Re: Fender Champion 40 as a modding platform
« on: April 26, 2021, 01:54:34 PM »
After checking the schematic, a very convenient solution could be to replace the TDA's 47K input impedance resistor R409 with a 25K/25K voltage divider (or a pot). This will push the hiss close to the noise floor and significantly increase the SNR ratio. And as an extra benefit, the amp is going to have a much more home-friendly volume range (currently 4 is my max)

I'll keep updating the first post with some progress

This sounds like a very good idea!  Let us know how it turns out!

Schematics and Layouts / Re: Roland JC-40 Schematic
« on: April 13, 2021, 04:29:51 PM »
I don't have the schematic, but would also love to see one.  This is a neat amp!

Tried to upload, but it's about half a meg bigger than the 5Mb limit.  If you want to bump the limit, I will attach.   :)

edit: nevermind, zipped

If you'd like to share it unzipped, I've adjusted the limited from 5mb to 7.5mb.

Schematics and Layouts / Re: Roland JC-40 Schematic
« on: April 12, 2021, 09:01:21 AM »
I don't have the schematic, but would also love to see one.  This is a neat amp!

Honey Amp / Getting started with your Honey Amp
« on: April 03, 2021, 09:05:08 PM »
Thanks for purchasing your Honey Amp!  Time to put it together and start making music!

None of the parts in your kit will be labeled to match component numbers in the schematic.  IE, a capacitor won't be labeled "C1."  This means that you need to know how to read component values.  Luckily, this isn't difficult and there are a lot of resources to help you along the way.

AMZ's Capacitor Calculator:
Capacitors have varying types of labels on them.  Electrolytic capacitors (they look like tiny soda cans) are usually labeled with plain text that will tell you the size and maximum voltage of the capacitor (10uF / 63v etc).  Pretty much all other capacitors use a code.  To break this down, use the link above.

Resistor Calculator:
Resistors don't typically have values printed in numbers on them.  Instead, resistors use color bands.
 Thankfully there are charts, graphs, and calculators online available to help you decode this color band system - I like this one for it's simplicity.  It's easy to use, and it makes it easy to start learning how the color codes work so they make sense.

The rest should be pretty straight forward by following the silk screening on the PCB.  IE - it shows the direction to put the IC in, same with transistor and even diodes.

Now that you have identified your components, it's time to start soldering.

Always start with the shortest objects first.  When I say this, I mean the components that are the closest to the board.  In the case of the Honey Amp, it works well to start with the 1n4148 diode and resistors.  Put them in place, bend the leads slightly and then turn the board over.  Solder them on and then clip the remaining lead.  Continue on until you have installed the tallest component.  Now you are ready for off-board wiring.

Honey Amp / Honey Amp Docs
« on: April 01, 2021, 09:37:12 PM »
Enjoy  :tu:

Honey Amp / Honey Amp FAQ
« on: April 01, 2021, 09:27:41 PM »
Q: Why was the SSG-AMP-1 kit eventually called the "Honey Amp"?
A: My first build using the printed PCBs went into a tea tin.  The second one went into a Honeywell HVAC control box.  I trimmed the "we" in Honeywell and it made "Honeywell" (Honey II).  This means the first one was the Honey and I decided to go with the name.

Q: Where can I purchase a Honey Amp kit?
A: Currently these are not for sale.  The kickstarter has finished and I am mid-process shipping the kits out from that.  Once this is completed, I will be adding a store section to where you can purchase a kit then.

Q: How much power can I expect this to make?
A: The power output is dependent primarily on impedance of the speaker the amplifier is connected to as well as the supply voltage applied to the board.  Obviously there also needs to be sufficient input signal strength.  Maximum power for this board is 1.6w on a 16 ohm load using 16v supply voltage.  Using an 8 ohm speaker the maximum power output is going to be 0.85w powered by a 12v supply.  And lowest power comes from a 4 ohm speaker on a 9v supply coming in at only 0.35w.

Q: Can I use this for electric bass?
A: You sure can!  If using this for electric bass, you will want to adjust the output capacitor from the stock 470uF to somewhere around 2,000uF.  You will also probably want to make some changes to the tone stack (adjusted to taste).  Please remember that using a proper electric bass speaker will really be necessary to make this sound decent.

Q: Can I play music through this (mp3 player, cell phone etc)?
A: No problem!  I do this regularly with mine, it works great to drive some speakers for my desk when I want to listen to music on my laptop.  Use the aux input on the board and crank up some tunes!

Q: What about power supply?  What should I use?
A: Most little amps like this end up being powered by batteries, but any stable DC voltage supply ranging from 6v to 18v will work depending on what impedance you have hooked to it.  Recommended max voltage for 4 ohm will be 9v, max for 8 ohm is 14v, max for 16 ohm is 16v.

Q: Can I get clean tones from this amp?
A: While this amp does best for crunchy tones, it does have some tasty clean sounds as well - just at lower volumes.  To get this dialed in, start with gain all the way down and volume at half.  Turn your volume up to the desired level (it may well be maxed out and that is okay).  Then slowly turn the gain knob up until it starts to get a little distortion, back it down just below that point and that is the loudest clean setting you can get.

Does the amp still turn on?  Is there any sound at all coming out of the speaker?

Gamechanger has created and released the Light Pedal.  This is a spring reverb pedal that incorporates not only real springs, but also infrared optical coupling to achieve their sonic offering.  This sounds very interesting, but it lists for 289 EUR, about $350 USD.  I've never spent remotely that much on a pedal, but maybe someone will?

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