Archive for the ‘Pearl’ Category

Pearl DS-06 Distortion

Thursday, September 10th, 2015


What is it?
Pearl DS-06 Distortion. Made in japan, early 1980’s.

Simply an overlooked gem. Somehow this unit has slipped through all the classic listings while the overdrive and a few others in this series is highly considered and still receive praise from time to time. It is a distortion unit, so i wasn’t expecting much. The controls did look somewhat out of the ordinary, but i didn’t bother to do much research as the opportunity rose to get one in a decent deal. Once the unit arrived, i took it for a spin and snapped couple of photos. Opening the unit up showed very neat old school traces with pretty hand drawn feel to them. The board looked also pretty full, so at this point it became rather obvious that the electronic design was not your standard rip off of any popular design.


Flipping the board showed the terminals in use, but all the rest is laid out in a beautiful manner. The heart of the driver is a JRC opamp and i mostly due to those terminal strips, i was expecting to see a stacked board setup with board mounted pots. Not the case here.


The second board houses the switching part, but all the pots and the rotary switch are hand wired. Clean work and production must have been quite labor intensive. In other words, this is a prime specimen of japanese craftmanship of the early eighties.


To be honest, none of the pedals from this Pearl series have been poor. Quite the contrary. But. That’s not all.

No research, so the features were not familiar to me beforehand. At the first test run, the Out level and Distortion knobs acted like expected. But as for so many other distortion units, the tone controls are called “Spectrum”. Instead of just single tone control, we have a six position rotary switch for six different frequency range settings, accompanied by a Level knob. These six modes set the general, or a peak frequency for the overall tone and the level knob set the boost amount of that frequency. With this setup, the available frequency range is next to unlimited.

Sadly, no schematic available.

How does it sound?
At first, like so many other distortion units. Decent, but not great output level with well working distortion control, which ranges from well balanced overdrive to full-on thick distortion. Nothing mind blowing, until we start to tweak the tone with with the spectrum controls. Then. Boom. This beast does everything from glass shattering treble mayhem to massive mid hump that rips the heart out of any tubescreamer, to all the way to a wallpaper removing, bassy doom distortion. And everything in between. Even the worst sounding settings will serve a purpose. If i’ve been calling some distortion units versatile, this word is very much insufficient here.

Good distortion tones with one of the greatest tone control sets i’ve ever heard on a distortion pedal. The controls are not amp-like, but extremely usable. Simply, an overlooked gem.

Pearl PH-03 Phaser

Friday, July 11th, 2014


What is it?
Pearl PH-03 Phaser from Sound Spice series. Made in japan around early 80’s.

This is one if those boxes i managed to buy off from mr. Lindèn and it came with reasonable price too. The unit is very lightly used and it even has its own retail box with minimal wear. These do not come by every day. For example, at the time of me writing this, there are no units listed on eBay. According to, these usually sell for something between 50 and 100 USD. This feels a bit low as there are not that many units available. Maybe this phaser simple hasn’t had the cult status of the overdrive or octaver boxes from the same series. I personally think it should. Here’s why.


Classic hand drawn acid trip traces on a fat old japanese style PCB gives out eye candy that you can expect from similar boxes of the era. Solid quality and beauty combined. Pedal is made out of two different boards. One for bypass switching and the main board. Flipping the board over gives out a view that one did not expect to see in a phaser. I was waiting to see your standard Phase 90 derivative or something similar where phaseing is done with discrete JFETs. No. There are obvious modulation stages, done with dual opamps and an LFO, which doesn’t seem that standard either. The big chip in the has been painted black so tinkerers would have a hard time finding out what it is. Since there’s no telling what the chip is just by looking at it, i thought i’d check for a schematic if that would shed some light on the matter. There is an old factory schematic up at FIS. No luck. The schem says it’s “exclusive use”, which in pedals, usually means  that it isn’t that secretive, nor is it made exclusive for this design. Usually these are your standard parts that are just obscured. I didn’t want to stop there. I found an discussion about the circuit on FreeStompBoxes forum ( you may need to log in to see it). Anyway, someone had bought one of these as a defunct unit and found MC14069 chip where IC4 should have been. So it’s pretty obvious that someone else had already tried repairing that unit – by replacing the chip for something that clearly isn’t the right one.


User Tube-Exorcist suggest that the original chip may be a AM79C11 (can’t find any info or datasheet about it), a obsolete quad JFET. Which would definitely make sense.

The design isn’t your run of the mill phaser. The LFO isn’t anything too exotic, but the modulation stage is. May the chip be what ever, it isn’t usual to have a quad JFET DIP16 chip in your phaser. If the chip is (and it probably is) a quad JFET, that would mean that the design is in its heart a four stage phaser. Still a sort of derivative to Phase 90, but not exactly. Either way. This offers some mystery and i like it. Besides, the four effective controls are also something that every other phaser doesn’t have.

How does it sound?
Lushy and wild. Not as deep as EHX Small Stone, but a lot more powerful than your average Phase 90 and its derivatives. From mild, slow sweeps to nearly massive wobble. Feedback and manual controls offer a lot of room for variation. It is very nice sounding phaser. Probably one of the greatest ones with only four phasing stages.

Pearl SU-19 Noise Suppressor

Saturday, January 4th, 2014


What is it?
Pearl SU-19 Noise Suppressor. Stereo noise gate, made in japan, early 80’s.

I’m not that sure if get the whole noise gate suppressor thing. I mean, what’s the idea? To use too many noisy and bad sounding designs in a chain, so that you’ll need a device to kill signal? Well. For me personally, the need is not there. I just happened to get a nice deal on this unit, so i though “why not”. Thanks to J. Lindén of Linden Guitars. Only bad thing is that the bottom rubber has gone missing something like 20 years ago. Su-19 has two channels that can be tuned one by one. This brought up another question, “why?”. After thinking about it for a second, the other channel can be used to kill the excess noise coming from the guitar and the second one to do the same for the signal that leaves the pedal board. Or other option would be to use one channel to tame the pedalboard noise from before the amplifier input and the other to tame the other units from amp’s effect loop. Either way, quite a cool idea. I do get the gates when used on drums when recording, but for the guitar? And two of them? Maybe i just haven’t been in need for high enough gains to understand that completely.


To take the box open, one needs to unscrew the battery door and six screws that hold the thick metal plate in place. The box then shows the board that is beautiful on more levels than one. Notice the symmetry for each channel on the board trace layout.


Japanese style crowded and thick board. Very crowded. Didn’t feel like ripping it all off, so you’ll just have live with this image of it.


There’s even some point-to-point mojo near the pots. I would say that the unit is very well made. Just like all the other units in the Pearl series.

How does it sound?
Very silent on most settings. The controls let you dial the threshold and decay speed to exactly where you want them. The fade-out is smooth and when dialed to one’s liking, it’s barely noticeable. As noise gates come, this is very nice item with both, user and collector value.

Don’t you just love it when guitar gear never gets too old or obsolete?

Pearl OD-05 Overdrive

Sunday, December 8th, 2013


What is it?
Pearl OD-05 Overdrive. Made in japan, early eighties.

This must be one of most desired overdrives on the planet. And for good reason i might add. I don’t know how many units were made, but the amount must be a lot. There’s almost always one for sale on eBay, so this ain’t exactly a rarity but the prices these go for do tell us something.

Opening the unit’s six screws show peaceful board with strong, solid traces and neat, professionally made solder joints. Just what one would expect from japanese early eighties pedal.


There  is an factory schematic available online (plus numerous DIY projects), which opens up what this design is made of. There’s a buffer first, then a slight boosting gain stage to drive the  semi-parametric EQ. Couple of filters follow, and then the main gain stage. This has symmetrical clipping diodes in feedback loop of non-inverting amplifier. Something that we see quite often in overdrives that try to emulate tube saturation. And of course, an output buffer. All this with electronic JFET switching and well designed ins and outs.

Pearl-OD05-guts3There’s two JRC4558D dual opamp and a handful of transistors in the signal path. The output level is sufficient as the main gain stage is there just before the output buffer. This way the tone control or filters won’t affect the output.

Well made boxes indeed. I think the prices are going to slightly rise on these units in next ten to twenty years. It is a classic without massively marketed reissues – actually, no reissues exist at all.

How does it sound?
Natural sounding overdrive with great addition of semi-parametric EQ to tune it to suit your guitar better than most other classic overdrives. The sound has some same characteristics as your Tubescreamers, but the EQ lets you control the hump point. It sounds very good and usable. Recommended pedal. Strongly recommended.

Pearl F-605 Electro Echo Analog Delay

Friday, October 4th, 2013


What is it?
Pearl Model F-605 Electro Echo Analog Delay, made in japan around 1977-79.

Saw this unit for sale and couldn’t help myself. Even if it meant that i was to eat dry bread for the rest of the month. Price wasn’t too bad, and i wouldn’t sell this for the price i got it – never. As analog delays come, this may be one of the greatest. It has input and output level selectors, which make it usable with synthesizers and other devices with line level output. In/out level settings depicted in the photo above work reasonably well with electric guitar.

Three modes on the right are Delay, Chorus and Duplex. Duplex, like the name suggests, mixes both delay and chorus together, resulting in quite spacious soundscapes. Unit runs on 12V DC supply or two 9V batteries. The latter seems to be quite a standard for these older designs. The photo below shows the circuit board. It’s pretty crammed…


But the traces are neat and the design looks pleasing. That box could have housed a bigger board, but i do find this tightness intriguing. Board designer shows some great disipline. I didn’t take the pots off, so you’ll need to live with a shot of raised board. Yup. It is crammed.


The chip responsible for the delay is MN3005, a 4096-stage long delay BBD (Bucket-brigade device). I know i should dig deeper to the design to see what’s really happening in there, but this seem quite complicated analog delay device to begin with. I may have to start with something a little more straight forward.

Anyway. As a closing, here’s a shot of the bottom plate. Everyone will get what the text means, but i think that grammar beats even mine.


How does it sound?
One of the best analog delays i’ve played with. Versatile design that has useful modulation section. Not really sure if these units were meant to be guitar effects in the first place, but it works and sounds.. Well. Analog. Overall, analog delays have their own character which is in many ways worse than modern PT2399 or otherwise digital based delays. This one has cool vintage clang to it, which is not too bad. Unit may be collectible, but i can already see myself using it next time i’m in studio…

UPDATE! There’s a traced schematic up at Freestompboxes (for those who have an user account). This shows there’s no regulator at the power supply side. On battery use, the unit uses 18V, but the dc jack has 12V 300mA printed next to it. This being said, the unit sounds awesome on battery and a power supply that gives 15V and >100mA out. Since the batteries can handle about 20 minutes of use and 12V supply sounds like s**t, i’m under impression that the label next to DC jack is in error. If you have one, feed it with 15V supply and be amazed.