Minimus 7 PZ-2.2 Mod DIY Circuit Board by Pete Basel

Here's an update of my PZ-2.3 build:
Too much of that lately. Really need to retire and enjoy some music ... :music:

Nice work Stuart, very nice!

Anxious to hear as to where you run the tweeter level. I'm finding full up to
be fine when they are in (almost) the corner.
 
Anxious to hear as to where you run the tweeter level. I'm finding full up to
be fine when they are in (almost) the corner.

Getting similar results. My 60"x30"ish workbench is set in a nook. When placed flat on their bottoms near the back corners the L-pads are wide open. As they are pulled forward and inward from side walls, and lifted on short tilted stands, I'm dialing them down as much as nearly mid position. Still experimenting with different placements and music types -- they are proving their versatility and sounding nice!

I often run PZ modded M-7s on stands away from walls with a pair of small subwoofers dialed in to achieve a satisfying balance. But I like to take a pair along when on the road, and also to set up when working in spaces that lack an installed audio system. To my mind the portability of these little speakers is a chief value point. In that regard, adjustable tweeter level is a welcomed enhancement to the elevated performance already realized by the PZ-2.X mods.
 
Has anyone considered attaching the crossover to the back of the speaker in a project box and running the wires into the back to speakers? It would give more cabinet volume. Would there be a reason not to do this other than cosmetics?
 
Has anyone considered attaching the crossover to the back of the speaker in a project box and running the wires into the back to speakers? It would give more cabinet volume. Would there be a reason not to do this other than cosmetics?
 
Has anyone considered attaching the crossover to the back of the speaker in a project box and running the wires into the back to speakers? It would give more cabinet volume. Would there be a reason not to do this other than cosmetics?

No reason the crossover can't be external to the speaker cabinet. Zilch did it that way while exploring all the crossover variations in the Minimus 7 Loudspeakers - Measurements thread.

Though you might not realize any low end performance advantage. Zilch found no significant difference when comparing measured response of crossover mounted inside vs outside the cabinet:

Cab Volume Study.jpg
 
I'm calling the schematic for use with an Lpad PZ-2.3 and it is attached, R2 should
be shorted and the Lpad hooked up directly in front of the tweeter. An Lpad is not
exactly like a pot, but that's how I drew it, just wire in and outs as shown.

Hello Pete & All -
I'm new to ALL of this, so be patient please!
About the L-pad - I see in the photo that it has three "terminals" or connector tabs, and in the "PZ-2.3_LPad" schematic it seems to be connected in three places: to the two circuit strips and to the positive tweeter terminal. So.... which "terminal" connects to which?
Is this right - the two outside "terminals" connect to the two circuit strips, and the center "terminal" connects to the tweeter? And if so, is there a positive and a negative for the L-pad connections to the circuit.
Thanking you & all & best wishes for the holidays.
 
Hi Joe, We are talking about the LPAD from PE part number 260-248 just to be clear
that Stuart used.
I think it will all be explained if you look at Stuart's post #40 through his pictures.
I will also try to explain, here are the instructions from PE:
PE-LPAD-260-248-parts.gif

And here is a picture from PE, note that the terminal numbers are stamped into the terminals,
1 is the rightmost one and 2 in the center:
Capture.PNG

This all agrees with Stuart's pictures in post #40, note also how he had to cut the PC board to clear the LPad.
Terminal 1 gets 2 black wires one to he crossover and the other to the negative tweeter terminal. Terminal 2
gets a reused blue wire probably with the slip on terminal for the tweeter that goes to the positive terminal.
Terminal 3, green wire, goes to the circuit board as shown in Stuart's picture:
index.php
 
I've looked at this before and I should say, color me impressed.

I have several sets of M7's - I could consider doing this - maybe use them as desk speakers?

I don't have a bandsaw and haven't "built" any boards at all - this doesn't look hard, so I might just give it a go and use a hacksaw or file. Or something, LOL. Thanks for all the info.
 
Pete B - thank you for your clear, helpful, prompt reply.
I'm looking forward to listening to my new! improved! speakers. But I'm already enjoying this great website with knowledegable members like you!
I hope you & all enjoy the holidays.
 
I was thinking of using copper tape (sold for garden slug control) glued to masonite to make the board rather than just connecting wires. Any thoughts?
 
Pete B,

I already have installed the litekeys kit on numerous 7's. Would I be able to recognize any sonic benefit by implementing any of the PZ2.2 HF crossover modifications on these or should I just keep them as they are? Please bear with me, I'm a newbie.
 
Hi Joe, We are talking about the LPAD from PE part number 260-248 just to be clear
that Stuart used.
I think it will all be explained if you look at Stuart's post #40 through his pictures.
I will also try to explain, here are the instructions from PE:
View attachment 1064142

And here is a picture from PE, note that the terminal numbers are stamped into the terminals,
1 is the rightmost one and 2 in the center:
View attachment 1064146

This all agrees with Stuart's pictures in post #40, note also how he had to cut the PC board to clear the LPad.
Terminal 1 gets 2 black wires one to he crossover and the other to the negative tweeter terminal. Terminal 2
gets a reused blue wire probably with the slip on terminal for the tweeter that goes to the positive terminal.
Terminal 3, green wire, goes to the circuit board as shown in Stuart's picture:
index.php

A pot (L-Pad) on the Minimus 7's, that's new. I know I've seen a few different Min7 hacks, I have yet to try one.


How did they turn out? Do you have a schematic for your build? Ill look through this thread to see if I can find it.
 
Here's a schematic I use for my own reference:

View attachment 1274413

This is the L-pad version. There is also an option that uses a pot (PZ-2.2). It's worth reading through the whole thread. Besides the build options, Pete's included a host of tips on PCB construction and parts list components.

I need to pick up a set of 7s, I've had many sets of them, just never seem to stay.. looks like a fun project tho!
 
A pot (L-Pad) on the Minimus 7's, that's new. I know I've seen a few different Min7 hacks, I have yet to try one.


How did they turn out? Do you have a schematic for your build? Ill look through this thread to see if I can find it.

This is essentially the PZ mod detailed in this thread that was based on my design with
a few tweaks from Zilch:
http://audiokarma.org/forums/index.php?threads/minimus-7-loudspeakers-measurements.199790/

The schematic is in the first post here but R2 should be 15 ohms with the 25 ohm pot
wired across it if you want the pot level control.
Stuart's setup with an LPAD is better, didn't know that they made LPADs that small.
Short R2 if you use the LPAD.
 
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