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Messages - joecool85

#1
No buffer needed between the power amp and the preamp (Bluesbreaker).  That said, I've never used a BB as a preamp.  You won't know if you like it till you try it.  My guess, you won't have enough tonal control.  You like the sound of them which is great, but you don't send it into a flat eq'd amplifier - you send it to a guitar amp.  Even when you set a guitar amp eq to look flat, it has a large mid cut and sometimes other shaping.
#2
Amplifier Discussion / Re: 12w Marshall
August 08, 2022, 08:51:11 AM
Great work!  I split the topic though and made this it's own so it can be an easy resource for others later.
#3
Quote from: Carriage on July 18, 2022, 05:38:17 AMParts have arrived from tayda.
You cannot view this attachment.

How's it sound?
#4
Quote from: smadin on January 18, 2022, 07:54:56 PMThe great thing about DIY practice amps that run off 9V power is that there are so many to choose from! (The other great things are that they're inexpensive and usually fun and easy to build, of course.)

Off the top of my head:
  • The aforementioned Honey, of course, which I had a blast building. (and I'd definitely be interested in a Honey II with a different IC!)
  • The Noisy Cricket Cabell mentioned.
  • I got started with runoffgroove.com's Ruby, and their Little Gem mkI and mkII are also worth a look. They have some mod suggestions for their designs, as well.
  • Bruce Zinky's Smokey is as simple as it gets, it even omits the Boucherot cell from the LM386 datasheet's "minimal" schematic. (The Noisy Cricket page I linked also shows a couple of simple Smokey mods.)
  • At the other end of the spectrum, Electrosmash's 1wamp crams in all kinds of features. Looks like kits/PCBs aren't currently available, but full schematics, KiCad files, etc., are hosted on their forum.

I'm going to go ahead and revive this thread because I'm interested in a comparison between the Honey amp and the 1wamp.  Could you share thoughts on this?  The Honey amp has very similar circuitry, including the same lm386, transistor preamp, and BMP tone control.  The Honey's tone control is dialed in with different values though, mimicking the frequency response of a Vox AC30 top boost channel.  And of course the Honey uses the preamp for primary distortion rather than the LM386, allowing for use of master volume control while using high gain.
#5
I'm glad someone else is enjoying playing with the PAM8302a boards from Adafruit - they're cheap, decent quality, and provide 1.25w on 8ohm speaker or 2w on 4ohm speaker, which is pretty great.  And real easy on batteries because it's class d.

At one point I had thought about making a class d version of the Honey Amp using this board or similar.  This idea has been put to the back burner indefinitely, but I do have plans for a larger class d amp in the works.

Also, I'm not a fan of a Tube Screamer as preamp but if it sounds good to you, there isn't any technical reason not to do it.  As a good starting point, I recommend something more like the Marshall Gov'nor: https://www.electrosmash.com/marshall-guvnor-analysis
#6
Late to the party, but still here - we've found four new amps that were released during NAMM 2022.

Blackstar - Jared James Nichols mini amp (customized Fly 3): https://www.musicradar.com/news/blackstar-jared-james-nichols-mini-amp

Fender - Frontman 20G (Basically like the old Frontman 25R but without reverb and using an 8" speaker instead of 10"): https://www.musicradar.com/news/fender-frontman-20g-guitar-combo-amp

Line 6 - Catalyst series (New and upgraded versions): https://www.musicradar.com/news/line-6-catalyst-amps

Yamaha - THR30II (10th anniversary models in special colors): https://www.gearnews.com/namm-2022-yamaha-thr30ii-10th-anniversary-models/
#7
Quote from: Loudthud on June 15, 2022, 05:05:14 AMInteresting that it uses an external power supply. The jack on the back looks like the same one used on pedals.

This is becoming quite common on small amps and heads.  The Yamaha THR series does this, as does Orange Micro Terrors, Hughes & Kettner "Spirit" amps, Vox MV50 series and more.
#8
Quote from: willpirkle on June 13, 2022, 10:08:21 PMYep - I didn't get the name of the company who did all of them, but was told something similar about the power amps, and that each model was designed in partnership with each respective company, so there are differences in the preamps that could be interesting to study. Have not seen any schematics for any of them tho.



It is the parent company, Boutique Amps Distribution.  http://boutiqueampsdistribution.com/

They own a ton of companies now:
Bogner
Diezel
Egnater
Friedman
Morgan
Soldano
Synergy
Tone King
Wampler
#9
Quote from: BenGunn on June 03, 2022, 06:19:15 AMHow many posts do I need to create to get access to the PM?

Just 1 post.
#10
Long known for their high gain tube amplifiers, Soldano has decided to dip their toe into the solid state arena with their new amp, the SLO-Mini 30.  The SLO-Mini 30 is a small 30w head, with two channels and an absurd amount of gain.  Priced at $249 USD it is also (by far) the least expensive Soldano unit.  Well worth watching the video!


https://www.guitarworld.com/news/soldano-slo-mini
#11
Quote from: krunssg2w on May 31, 2022, 12:50:25 PMA follow up for question three above. If I decide to remote mount the AUX in and headphone jacks, what are the specs for the non-PCB versions of those jacks? On Digi-Key (for example) I see many jacks with 2, 3, 4, and 5 contacts for mono, stereo, TRS, TRRS, TRRRS. It's confusing  :P

It would be nice to use this so headphones have both 1/8" and 1/4" support -- https://www.digikey.com/en/products/detail/amphenol-sine-systems-corp/ACJS-MHD985/10443364, but I'm not sure how to wire it up.

As far as the AUX in is concerned should that be stereo 3-pin connector?

Links to recommended chassis-mount jacks on Mouser, Digikey, or Jameco, etc would be great!

Thank you!
Ken

For the aux input jack you will want a non-switched TRS (standard 3 pin stereo jack).

For the headphone jack you will want a TRS with switched pins on tip and ring.  This makes it a 5 pin jack.  When you don't have anything plugged in, the switches are closed and pass signal onto the speaker.  When you plug headphones in, it opens those switches and the signal goes to the headphones.

As for links, this is what I use for the kit for aux input: https://www.mouser.com/ProductDetail/CUI-Devices/SJ1-3523NG?qs=%2Fha2pyFaduhZ3BJrEKA2ZtL3QjeZizhqabaSR3Zt9OM%252BTMR%2FuSuQ3A%3D%3D

And for chassis mount, this would work well: https://www.mouser.com/ProductDetail/Switchcraft/35PRM3?qs=Mv7BduZupUiFtp5UCPt0Jw%3D%3D

For the headphone jacks I use these: https://www.mouser.com/ProductDetail/CUI-Devices/SJ1-3525NG-GR?qs=%2Fha2pyFadugo%2F194Ni2mldtHbvbWEI5Gmsq5myxkxhxCHzvQ6NSWVw%3D%3D

And something like this would work well for panel mount in 1/4" (use an adapter to step down to 1/8"): https://www.mouser.com/ProductDetail/Amphenol-Audio/ACJS-MIV-5?qs=t8%2F5FiDdxGbV%2FTm03ByMkg%3D%3D

These are listed as 5 position sometimes, but really they are 3 position jacks with 2 poles for the switches.

Hope this helps!
#12
Quote from: krunssg2w on May 31, 2022, 12:29:31 PMHey! I'm a little late to the game, but started building out my Honey Amp PCB this past weekend. My intent is to use an 8 ohm speaker from an old Fender Champion 30 amp and likely power it with a 12V wall wart. I am building the "clean buffer" version, as I will be using this amp mostly to bench-test guitar pedals (a new hobby!)

My questions for the clean buffer build are:

1. C0 is shown on the schematic as 22pF. Does the type of capacitor matter? I assume any ceramic disc, MLCC, or box film cap would work, but wanted to check. I have a 22pF MLCC on hand and plan to use that.

2. The third line of the clean buffer instructions says "Attach C3 input to C2 + pad. [Audio jack] Input + will now need to be connected to pin 2 of RV1."

Can I get some clarification on these instructions? For the second part, it looks like the easiest solution is to solder a jumper between pads 3 and 2 of RV1?

I'm not sure about the first part -- C3 is soldered in place, correct? And I guess a jumper on the underside of the PCB between the pad of C3 closest to C0, and the C2 + pad? It's not to the pad of C3 closest to C7, correct?

3. Unrelated to the clean buffer alterations, what is the best way to mount the PCB in an enclosure? I will likely use PCB-mounted jacks for J2 and J3, but use wiring to remotely mount the Vol and Tone knobs. What's the best way to secure the PCB to allow access to the aux and headphone jacks?

Many thanks!
Ken


Awesome that you're building the clean buffer version.  This version uses the clean buffer of the Crybaby wah wah pedal from Dunlop and sounds really great.

1.  Yes, any 22pF capacitor is fine to use.

2. For C3, you will use the pad closest to C7 and the pad of C2 with the + on it.  Basically you are turning C3 90 degrees counter clockwise from where it is silk screened on the board.  If you have already soldered C3 in the stock location, you will need to remove, rotate by 90 degrees, and resolder.

For the second part, take the positive (tip of guitar plug) on the input jack and wire it directly to pin 2 on the board.  This will send it straight through to the circuit, pin 3 will be completely disconnected and of no use because you aren't installing a gain control.  No jumper required.

3. I have always mounted the board by the onboard potentiometers I spec with the kit.  Past that, you could use PCB edge mounts like these: https://www.adafruit.com/product/1116
#13
Quote from: BenGunn on June 01, 2022, 08:42:58 AM
Quote from: phatt on June 01, 2022, 03:03:40 AMHi Ben welcome 8)
Regards to IMG_4223.1.JPG
My guess is that green wire you mentioned goes to the Chassis.

The idea is to re-route how the ground paths return to the main Common/Ground point,, which is the Chassis. I'm not sure about the 2 dots?

It would be best if you PM "bajaman" as he will be able to explain it to you.

Yes it must be hard when you have to translate.
hope it helps, Phil.

Thanks for the answer, phatt! But, unfortunately, I don't have the rights to send private messages. Maybe bajaman will appear on the forum and answer my questions...



You should be able to PM now, you just have to have a few posts to your name first.
#14
Amplifier Discussion / Re: My K-20X
May 31, 2022, 11:40:00 AM
Quote from: Trino on May 28, 2022, 05:38:30 PMHello joecool85 Hello, I need a thing
, can you give me a photo of the pcb of your k20x please?

Anything in particular you are looking for?  Earlier on in the thread I have pictures posted of the topside of the board.  There are also attachments showing the schematic as well.
#15
Quote from: phatt on May 07, 2022, 06:37:30 PMYes open back delivers a more spatial sound hence fuller effect especially in small spaces but can present weird sonic issues in larger venues.
You may notice that a lot of big pro gigs tend to use closed back cabinets.

A player friend noticed this weird effect at an old wooden school gig where his open back rig was giving him a crossover of out of phase in the position he was limited to in the building. It can mess with your brain and the sonic result can be off putting.

That does not happen as much with a closed back cabinet.
Although it can still effect a closed back cab it is not as bad.
Venues with big Glass windows can have really bad reflections.
Phil.

I never really thought about it as I don't typically play out, but just at home.  That makes a lot of sense though.