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Roland PMA-5 Backlight Installation

This is a backlight mod for the Roland PMA-5. It has been tested and really looks awesome. I had to work through issues such as, dimension constraints, power variances and transformer noise. LED backlights are too thick for this application. An EL panel, DC/AC transformer, buck converter & dc power filter was used. Except removing the LCD mirror, original shell and unit operation was left unmodified. The EL transformer operates between 1-4VDC and the unit power is 9VDC.


First obtain an operational unit. Tear down the unit to access the LCD screen. The rubber contacts probably will be stuck to the assembly. Carefully peel apart the assembly and remove the mirror sticker on the back of the LCD screen. Clean the screen from sticker residue with IPA. Clean all the rubber contacts, glass contacts and PCB contacts gently with IPA and a cotton swab. Remove any dust or debris.


Next you will need these parts.
EL Panel and Transformer
DC Buck Converter
DC Power Filter


The El panel should be cut to size and then the sides taped. I dismantled the EL transformer box and de-soldered the switch and led from the unit. A wire jumper was used in place of the switch so that it turns on when the unit is switched on. I then found that the optimal DC output of the buck converter should be at 2VDC. The transformer should be mounted in the exact location as the photo posted. I used tape to cover the electronics and placed then between the main PCB boards of the unit. Noise to the headphone output will occur if you route the EL AC wire across CPU chip on the board. Tape this wire to the board above the chip, do not cross this line over chips.



EXEF PSE 1000 M

Exef was a German manufacturer of electronic music equipment. This is a preamp with a programable effects foot controller, the EXEF PSE 1000 M. Three dedicated programable, pan-able effects options A,B & C. They can be saved in any combination as recallable, each with a send & return. There are 3 additional send & returns controllable as inserts. The Sidekick foot controller has a large floor display and can manage easily.

I dug this up from an auction sellers description and AI translated it.



World famous and good quality such as Bogner and Diesel
Germany is also known for its many guitar amplifier brands.

This is the famous machine "PSE 1000 M MK2 by EXEF" from Germany. This product integrates a programmable preamplifier and switching system. It's unique, and I don't think I've ever seen a product with this kind of concept. It was released in the early 1990s, and at that time it was expensive at about 400,000 yen, and it had a strong image of being a professional device. I don't think there are many people who know this brand because it disappeared without being popular with general users. It is also known that Mr. Hiroshi Shibasaki of WANDS at that time used the 1000 M MK2 during the WANDS era. In addition, Mr. Tomoyasu Hotei used the company's switching system LOOPER in the early 90's. ... apparently ...




If I find a manual or get a peek inside I will post additional information. I found this option, the mk2 exchange module in the gallery below. This would be nice to hook it up to a stereo tube amp. A long cable can send the controller front stage and back stage you have your rack.


Below is a list of products by Exef.

  • PSE 1000 M (preamp effects controller)
  • B300PR (300w bass amp)
  • VP-42 (guitar preamp)
  • VPA-260 (stereo tube amp 2x60w)
  • Concrete 260 (solid state amp)
  • 6 Shot (midi programmable guitar preamp)
  • Triton (3 channel tube guitar preamp)
  • 4 Tune (4 channel tube guitar preamp)
  • Jambird (guitar amp)
  • Looper (loop programmer for preamp effects)
  • MSW4 (midi programmable switching system)
  • Switcher (function audio combi switcher)
  • Micro Switcher

4 Tune


Sidekick, Switcher, Microswitcher, VP-42, Jambird & PSE 1000M


Looper, Mapper Plus, 4 Tune, & Additional Photos

Guitar Tunings

This post contains an alternate way to select pitch. I do prefer 440hz over 432hz but the number magic is interesting with in 432hz. Obviously we all know the benefits from strobe tuning and like our Peterson models. I always had a pretty good ear when it came to sound listening. Early on I experimented with self tuning by ear until an aha magic moment occurred. At these moments, I captured the offset by writing down the frequency in hertz of the tuning. This magic is specific to instruments, amplifiers, strings, intonation, picks etc. So please take a look and try my numbers to see if it might work for you as well.

First I will post the notes of my favorite tunings and then I will post the adjustments specifically for the E tuning. Obviously I lean more towards the up than the down. Despite this, I love listening to down tuned instruments.


EADGBE(Classic Tuning)


F#BEAC#F#(Unique sound)


GCFA#DG(This is one of my favorites. Unfortunately it’s right at the tension line of busting. Using .11 strings I’ve never felt a more punchy, and tighter sound.)


EADGBE, now if you look at the numbers of the adjustments, it’s more like close to E2 A2 D3 G3 B3 E4. I find it hard to replicate my favorite tunings consistently and easily. I wish there was a device that let’s you set the frequency instead of the note. Chromatic gets close, and then I just fine tune by ear. The reasoning why is later covered below, described as a floating ideal number instead of a fixed one.


82.3hz82.3hz77.5hz72.3hz
110.4hz110.3hz103.5hz97.3hz
147.3hz147.3hz138.5hz129.3hz
197.5hz197.3hz184.5hz173.3hz
248.3hz249.3hz232.5hz219.3hz
333.3hz333.3hz310.5hz293.3hz
Favorite Tunings @ 440HZ Chromatic Hertz (Target E)


I believe each individual wants to be in a thought, place or mindset when they listen to audio. Whether your feeling grounded to Earth, or blasting through the solar system, there is a specific frequency that you resonate with.
I like the idea of always changing, environments are always changing, strings don’t stay in tune through big environment changes. You need to be flexible and follow the sweet spot of listened sound as your environment changes, it will yield you the best results. Studios are different because their controlled environments. We use baffling, soundproofing, purposeful placement, temperature and humidity control. In these places, choosing a pitch that works best for the control area is idea.

… if you want to read more about “pitch


Here is what I put together, based a story that standard pitch was raised from 432hz to 440hz because concert halls gained warmer temperature controls over the past 100 years.

Explanation:
2.6F for every 1hz +/-
This is the offset adjustment from 440hz at 72F.

Procedure:
Take air temperature
Subtract from 72
Divide by 2.6
Sum is +/- new pitch standard set in hertz
Set into tuner and adjust guitar strings to EADGBE


I thought this abstract found online to be a good read as well.
I would discuss air density in the equation but it’s not a practical measurement.

Otari MTR-10 II 1/4″ Two Track Master Recorder

This post will cover a restoration for the Otari MTR-10 II reel to reel 1/4″ tape master recorder. There are many posts about this unit but I feel it lacks some key information that I will cover in this post.

First lets talk about tape. I am not an expert by any means regarding the subject but I want to pass along some information that I discovered. Many people discuss the issue of sticky shed on tapes but there is also another annoying problem, flaking. I have used some newly manufactured tapes and they seem to all have this flaking problem in which little dry bits of tape shed off during transport. Personally I prefer to use the Scotch Classic tape and here is the technique I run. I purchased some new in package tape and spooled it up. Pressing the Edit/Unload button and Fwd button I run the tape through the guides. It runs at a slower speed and the tape does shed strands but they are easy to remove from the guides. Then I repeat the process back to the spool. After that I clean my guides and apply Last Factory Tape head treatment. The reel runs smooth and it doesn’t shed any more residue. BTW the original Otari reels look way cool but I could not find them anywhere.


Next, I’d like to mention…. please don’t use motor oil on your capstan or any bearing parts that need lubrication. Use the manufacturer’s recommended oil lubrication, they mention it for a reason, an no it’s not snake oil. I say this because it is readily available and cost me $9 a tube. I contacted Otari directly and there factory still has it in stock. To avoid sending them a wire transfer to order it just contact AHEADTEK in the US/California to order some, they are Otari’s licensed reseller.


The 50 pin connector on the back of the unit that is used for the remote control option is a Honda 50 pin connector. Otari in 1970’s used the same connector from the auto industry MR50F & MR50M. The good news is that they are readily available on Ebay and you can also get cool break out boards with the connectors on them.


If your reel is wobbling a lot you may need to replace the transport hub. Alternatively check that the reel you are using is straight. If major damaged has occurred you may need to replace the transport motor assembly.


The audio oscillator built into your unit should work when input is selected. If it is faulty then the problem area will reside on your Audio Control Board. I pulled my card and noticed that a capacitor had exploded and possibly damaged other components. Instead of repairing, I bought a functional board used for less than $80. This feature will be helpful when calibrating and running additional tests.


Replacing the lights on the UV meters and transport controls are super easy. The original incandescent light bulbs were frosted but clear replacements work great. The UV meters use 8v (Axial Miniature lamp 100mA with leads) and the transport buttons use 5v (T1 3mm Pilot Lamp 60mA). When opening the UV meters be sure that the plastic adjustment pin is aligned before snapping the cover back on. Taping the bulb on before soldering definitely helps. For the transport controls you just gently pinch and pull the cap cover off. The bulb is inserted through a loop in the sides. Get the service manual so you know how to take apart the unit. SEE Photos.


Note: If the button does not work and only the light, the contact cup needs to be replaced. The original cup is approximately 10mm base diameter, 4mm in height with a 7.5mm taper base diameter. Pins 1&2 (light) pins 3&4 (switch). The inside ID switch cup housing is 9.8mm, the original old cups sat on the raised ring by the contacts when I opened them, possibly widened over time. A cup 9mm in diameter should place inside easily and prevent it from moving. The original switches are obsolete but reworkable. Bend up the 4 pins holding the plastic spring guard, careful to not let it lunge out. Behind the cap is a spring and the contact cup. They often break at the top where the carbon contact is located. I had to cut the diameter so that it would fit into the guide.



The head assembly easily comes apart for servicing. Use pure isopropyl alcohol for all cleaning of transports. A cotton swab is preferred and then use a lint free cloth for the rollers. Be sure to check inside the unit as well as under the panels for old tape shed and get that unit clean.


Please reference this list below for the plug in boards. Also I have included a picture of the extender card set.


This project is ongoing and I will continue to post more information about what I encounter. Below are some more pics and downloadable data.



Run the .stl of Calibration Tool in Prudaslicer and print then press fit the 2.5-2.6mm Allen keys into handle.

1X12″ Tube Amps “That Pack A Punch!”

I put together a list of some 1×12″ vintage tube amps that are way too loud for their size. These little beasts deliver unparalleled performance in a small footprint. Not many 1×12″ amps still exist that have heavy power supplies and tubes inside. The heat and the cramped space leads to other malfunctions down the road having so much power in one place. Common faults may be loose parts, broken solder joints, overheating PCBA’s and blown speaker.

My favorites are hard to narrow down, each model possesses it’s own unique character and tone. I currently own an Ampeg VT-120 but I was lucky to find one with clean pots. 80’s units tend to have those dreaded push pull pots but now there are some suppliers remaking the vintage style pots. I am still searching for a vintage 1×12″ tube amp that has a rating higher than 120W but it’s crazy to think why?

Please enjoy the photos I dug up for review and post any worthy models you would like me to add.

  • Randall RGT100
  • Dean Markley CD120
  • Ampeg VT-120
  • Peavey MX VTX
  • Carvin X100
  • Mitchell Pro-100
  • Fender 75
  • Mesa Boogie Mark I
  • VHT/Fryette Pittbull 45
  • Musicman 112RD
  • Park MV
  • MARSHALL JCM900 MODEL 4101

Keyboard Preamplifier ALBIT N-330

I am posting these pics and I am pretty sure none of you have this item. I picked it up from a Japan Auction House in mint condition. The color scheme on it is vintage and the build quality is very good. I have a synthesizer rack and use this device as an optional pass through if I feel the sound output is inadequate pre mixer. It gives you the option to also add three effects loops and trigger each one individually or run them simultaneously. The Low, Middle and High Tone controls each provide a frequency sweep control to locate the problem area and adjust level. The Low and Middle have an additional bandwidth control for range of adjustment. Unfortunately I was not able to locate any manuals or documentation for this unit.

KRK 15″ Studio Monitor Search

I was looking for a larger KRK studio monitor set and I came across a custom build for sale. These speakers posted on Reverb were selling for almost $2400, came with the stands and looked amazing. Unfortunately the cost at time was a problem and I let them pass by. I have found it very difficult to come across any other KRK 15″ 3 way studio monitor pairs.

Note: KRK Systems was founded in 1986 by a visionary working on such films as “Brainstorm” and “The Doors.” Frustrated by the fact he couldn’t find a monitor that gave him the clarity and accuracy needed, he began building his own monitors. 

One day a local to San Diegan posted a set of KRK 15P-3’s for a dollar. He was moving and just wanted them out of the house. I reached out and he said that no one wanted them so he dragged them to the curb for pick up. That night it rained and then they were picked up by collection. Bummer, it would have been the ultimate deal. Below are the pics of the three different KRK 15″ studio monitors that I have seen around since I started looking a few years ago.

Check out these monsters.

NAMM 2022 Visit

Below are some pics of the NAMM 2022 show in Anaheim, CA., overall I enjoyed the show. The highlights I thought were the showcases of effects pedals and suppliers relevant to those builds. I felt that the selection of synthesizer manufacturers was small. It was nice to see the old cats still there in the game, Oberheim & Sequential but who can afford those remakes. The reboot vintage look from Fostex seemed appealing and the headphones looked great, unfortunately no one was running the booth so I didn’t get a demo. I came home and bought new leather pads for my Sony MDR-7506.

Vintage Peavey Sampler SP SX II PC1600 & Kurzweil K2000R SCSI Zulu Emulator Build

I am working on a vintage sampler build. This rack set will include fully expanded Peavey SP, (2) SXII and a Kurzweil K2000R. Added control will be used by a peavey PC1600X. These Peavey units take the old apple ram modules and on the SP you have to set the jumpers correctly on the main board to enable the full use of the ram.


UPDATE: I have decided to move away from external storage rack units and run with the Zulu emulators.
Rabbit Hole Computing. It turns out that you can create .iso files using Power ISO of the Akai S1000 disks you have. Then you can set the configuration files of the zulu to read each scsi drive as a cd. For the Peavey gear, I had to order a scsi selector switch to jump between SXII and the Zulu drives because I kept getting out of phase errors. The selector box has the SP connected in the middle, and the two zulu boxes and SXII are connected to remaining locations. Doing it this way, I can have everything powered on and not worry about phase errors.

Inside the K2000R I fully upgraded it with Expansion Sound ROM and PRAM from https://sampler-expansions.dxp.pl/ Then I added an internal Zulu drive and configured it, this machine is loaded with sounds, plus I copied all my floppy’s to the emulator as well as the internal disk drive… pretty awesome.
So, keep in mind if you have the current OS installed in K2000R it wont read the Zulu. Zulu emulation is working on a fix for this problem with an update soon. I was able to move forward by rolling back the OS of the K2000R to V3.54.

Above are some examples of how I set my configuration files of the Zulu. Each folder can house the set of scsi drives. To make a change you just edit the pointing directory.

Below are some pics of adverts from the time period by Peavey.


Below are some internal pics from the internals of the Peavey SP, SX and PC1600.

I am adding an update here for those who may be confused about how the architecture of the Peavey SP is set up. Please remember that it is all apple based so the ram and the floppy is reflective. It will not accept standard floppy drives but need to be apple based. Here is a model of a verified floppy drive that will work with this unit. Sony MFD-17W-10 or internal label of MP-F17-10-10 SMM.

Don’t forget that you can stack SP rack units to add polyphony. Here are the instructions, additionally I am posting some photos of factory disks.