Visits

Wednesday, November 16, 2016

El cheapo power soak

Many years ago, when I was but a lad of 19 I had a 50watt valve amplifier and lived in a flat.
That amp was the Peavey Classic 50 head. It sounded great, but boy hoh by was it loud.

Back then I had a job repairing turntables and as a result had access to a catalogue of stuff that just wasn't available in the local Dick Smith (remember when they sold electronics components?).

Anyway, in said catalogue they had this thing called a speaker attenuator. It was a little pricey for my measly wage, but I thought that it might do the trick. It didn't and it has been sitting in one box or another for the last 17 years. That was until this afternoon when I fished it out and took to it with the soldering iron.

You see, I had an idea this morning, it was the same one that I had back in 1999.

I'd been on ebay and was searching for something when I saw a "power soak" that was cheap and looked suspiciously like the thing that I had in my workshop.

After a bit of searching on the commute, I came across this instructable and it turns out I'd been doing it wrong.

You see there was only solder on two of the three terminals, so I guess that I set about wiring it the wrong way.

Wiring it up the same as the instructable yielded the result that I was after so many moons ago!

I don't have the 50 watter any more, but I do have two Fives and a Fifteen.
Now the five can be cranked and not annoy the neighbours, but everything in my crappy little sound booth rattles and its a little unpleasant on the ears after a few minutes.

The fifteen on the other hand, gets too loud at just #3 on the dial.
Nice and clean at this point, but the sweet spot is a little further up the dial.

I've only tried out the attenuator on my Epiphone Valve Jr Half-Stack so far, but it worked flawlessly.
The amp can run full tilt and yield a nice gritty distortion, but be dialed down to almost nothing.

With this design, the amp sees 8 ohms at any level and is now at a nice neighbour friendly volume.

Update:
I got around to placing the power soak into an enclosure this weekend and try it out on my Fender Princeton. The results are good, but not as good as they were on the Valve Jr.

There are a couple of factors at play here at least.
The two biggest that I can identify are A: Power and B: Speaker interaction.

The Epiphone overdrives well and doesn't get nearly as loud as the Fender.
Sure its 1/3 the wattage, but that doesn't mean its only 1/3 as loud.
I've run them in stereo and they're not too different side by side.
The Epi isn't being drowned out by the Fender.
Though the fender does cause more rattling of the fixings in the booth.

The Fender does overdrive, but at maximum it is pretty fizzy and not anything like what you hear when running raw into the speaker at full volume.
From what I can tell, the amplifier / speaker interaction is where the great tone of this amp comes from. When the amp begins to distort, the speaker is working hard and lending its owe character to the overall sound. This seems to complement the amp's natural overdrive and also round out any unpleasant fizz. Either that or the assault on your ears means they can't pick out the nuances.

Dialing back the volume of the amp to (around 4 & 5) the zone where it straddles the clean/breaking up threshold and setting the power soak to just slightly higher than where I had it on the Valve Jr yielded a pretty nice tone. Clean and jangly with nice overdrive when hitting the strings hard.

I usually play with a neck pickup, but the bridge was better when using the power soak.
At a guess, its due to the same reason the overdrive at max volume wasn't great. The speaker plays a big part in the overall tone and maybe the lower frequencies are being rolled off a bit as well.

In conclusion, the price can't be beat for the control it provides over neighbourhood relations even if the unit does change the way your amp sounds. I'd love to try out a more expensive unit to see if they too suffer the fizziness that I experienced. I'm guessing that the answer would be yes due to the speaker not being driven the way it is intended. I still had very useable tone, but it is markedly different to the raw amp experience.

Your milage may vary.


Friday, April 1, 2016

Earthquaker Devices - Organizer

Hi Folks,

I know it's been a long time between posts but I haven't had much to report.
Everything is work, work, work.

I'm pretty sure you're not all that interested in balance sheets, economic order quotients or digging up tree roots and the intricacies of laying a flat garden path with recycled bricks.

Me either, but hey, that's my lot right now (Come on October!).

I did get a little reprieve and have been messing about in a friends studio, but nothing worth publishing yet.

A little way back there was a bit of spare cash and I spied a used Organizer pedal.
I'm a sucker for organ tones and I'm a lousy keyboard player so what's a man to do?

In earlier posts I've written about other pitch shifting devices such as the EHX Hog, Digitech Whammy, MXR Blue box and I think even a Boss OC3. Though the last two don't really count.

I liked the HOG, but it was too expensive and I had gear lust so it didn't last long in my collection.
There was a top end warble that I found to be a bit annoying for the price point. But this is just an artifact of the octave up pitch shifting.

I've heard it in the Whammy 4 and it is present in the Organiser (and POG and probably C9 too).

The Organizer is an interesting beast, but you'll want to use a nice clean power supply as it can amplify ripple from the DC input. I have a bunch of them and they vary within the same model designation, so its just a matter of messing about until you find a quiet one.

The manual suggests placing gain devices before it in the signal chain and after testing I can see why.
Any distortion after the fact will reveal clock noise from the delay chip on lag function. And if you're not using a clean power supply it will be even worse.

I would have thought that distorting on the input would have made tracking less accurate, but it works really well. I don't know the math or the way it actually works inside, but maybe its something about squaring off the waveform that simplifies things, but there is a harmonic component to distortion too so maybe I'm off the mark entirely.

What counts is the end result and it is pretty good.

The lag function "feels" like a delay when you move the knob, but I think may be its more akin to the halfway point on the HOG hold function (sort of like portamento on a synth). I'm not going to open it up, so I'll leave it a mystery.

Turing down the bass and dialing a blend of dry with the upper register can give a nice shimmer.
When coupled with reverb and delay the results are pleasing.
Dialing in the bottom end gives (as you would imagine) a nice full organ flavoured tone, especially when running into a Univibe (or clone) for that simulated leslie wobble.

Having seen the Decemberists this week, I know it's nowhere near the real deal, but still a really fund thing to play with.

I found the Organizer to be a fun and flexible pedal that I expect to retain in my collection (how many times can I keep buying the same basic thing right?)

Maybe one day I'll post a demo.....


There was an error in this gadget