Tuesday 5 May 2015

Audio Technika

 A friend of mine from the UK got me replacement 6V6GT tubes for my Laney Cub 8. It had been lying un-used for a year since the heater filament on the old tube, a Ruby 6V6, broke (I found that out by getting the schematic PDF, identifying the heater pins and using a multimeter to check continuity, yay!).

 Replacement tubes aren't readily available in India and I don't have a credit card that allows me to order online. So, I offered to pay and she being the nicest person I know in the universe got me two sets of tubes, one of which she paid for. A pair of Westinghouse tubes which sound all thick, twangy and juicy and chime bellishly when over-driven and break up very musically when plucking intensity of the strings is varied. The other set of tubes were Russian Military NOS (New Old Stock) tubes that sound like they would be good for metal. They don't break up the way the Westinghouse does and sound good on power chords and overdrive quite musically when cranked up. By now you may realize the musings of an analogue gear maniac, yes I own a Laney Cub 10 as well, two of the cheapest tube amplifiers that you can get here in India and I got them for a real good deal by buying old stock from an online retailer when the dollar shot up to 65 INR. I knew that the rupee wouldn't come down for quite some time so I went on a shopping spree buying everything at the old rates, a lot of people had the same idea I guess, so many times I would hit a blank after ordering something only to have it canceled and have the seller offer me the same thing at the revised dollar prices, lost at least two Boss NS-2 Noise Suppressors because of this.

Tube amplifiers by themselves are capable of nice tones with fat Strats, I have a Washburn X10 which is about a decade old now, my very first guitar. On a solid state I would be hard-pressed to hear the difference between the middle position single pickup versus the bridge humbucker, but with the Laney, the difference is clear as crystal, the tonal characteristic of each pickup is different and colours the sound differently depending on the position and this is very clearly audible and not just a golden ears phenomenon.

No analogue setup is complete without discrete pedals and to this end I am guilty of being partial to BOSS pedals.

 You will see the odd Digitech, EHX, and NUX pedals, but every other pedal is a BOSS. 3 different kinds of Distortion pedals, the Distortion DS-1, Blues Driver BD-2 and the Metal Zone MT-2.Three distortion pedals that cover completely different areas of the distortion spectrum despite their user manuals providing overlapping settings for Crunch, Overdrive and Distortion. The MT-2 can be made to scream or growl by putting the Equalizer GE-7 after it and scooping out the frequencies.

The DS-1 is one of those ice-pick sounding distortion pedals, going into an amplifier which is a little hi-fidelity can result in a sharp bite to the sound, can be very unpleasant. But going into a tube amplifier you can make it sing. The BD-2 on the other hand is amazingly versatile, you get your standard blues trip and you can also get this heavy crunch to a deep growling chug-chug rich in harmonics, very pleasant and heavy and could be used in a lighter metal setting.

The Digitech MultiVoice Chorus is one of those pedals I bought after I heard the expression, "lush chorus as thick as week old coffee on your desk". It is really lush. However if you are the MN3007 BBD chip fan this will sound artificial to you. The chorus enables you to add "Voices", which means that you can add more than one chorus sound going all the way up to 16 chorus sounds added to the dry signal. Think liquid-shimmer-warble-underwater and some more. Can sound metallic if overdone but it is a chorus pedal with just more than a Rate and Depth knob. Level helps you adjust the signal output.

The Stereo Memory Man with Hazarai (SMMH) is my first ElectroHarmonix (EHX) Pedal. I'd always dreamed of getting the EHX POG2 or the HOG2 for those organ like sounds but as it turns out, the SMMH was the first EHX to hit my collection. I also wanted the EHX 2880 multi-track recording looper but they shut down the manufacture and replaced it with something else even before that pedal ever reached India.

The SMMH is a delay pedal with a looper and a lot of "bells and whistles", the "Hazarai"- a pseudo Yiddish word for it apparently. So here's in the deal, this delay pedal gives you more controls than the average delay pedal. Normally you have Level, Feedback, Delay adjust, Delay Type/Length. The SMMH on the other hand has Blend, Decay, Filter, Repeats, Delay and Hazarai. So the main difference from a normal delay pedal here is that the Decay and Repeats are normally combined in the knob labeled Feedback in a standard delay pedal. You want the notes to decay fast you turn the Feedback down, you want them to stay longer you turn Feedback up. However, this doesn't make for any interesting effects on a delay pedal unless you count weird oscillations or Wall of Sound effects that are barely just spilling into the oscillation zone.

On the SMMH however, this separation allows you to create flanging effects, strange motorcycle type sounds. Filter adjusts the tonal characteristics of the delayed signal allowing you to change the fidelity of the signal to make it lo-fi if you want so that the delay sounds warmer and analog. Delay does what it says and Blend is the same as the Mix or Level knob for a delay pedal. The Hazarai knob allows you to switch between the various delay modes that are available.

Here are the guts of the SMMH, I bought this from a friend so while it belonged to him, the footswitch began to malfunction a bit because the brass contacts got oxidized, I opened up the switch, oiled and cleaned the contacts and put it back together, it worked like a charm after that. I took this photo then, it's 12MP so zoom in for a closer look.


The coolest thing is the looping function followed by the ability to tap tempo over the loop to change its beat, the loop is auto-quantized which is pretty cool and also if you turn the Delay knob while looping you can speed up or slow down the loop and create some amazing variations of your loop that can give you musical ideas on how to change the pitch of your lick to effect a certain mood.




The Nux Core is a modulation pedal that I bought because it was a good deal in getting all the modulation effects under one pedal. Flanger, Phaser, Vibrato, Uni-Vibe, Chorus, the works. all digital emulation but then since I need them only occasionally I don't mind having an emulation.

Interestingly there is this Indian company called Stranger which produces effect pedals. I happen to have a Chorus a friend left with me. I had heard forklore about how the Chorus was a copy of the Boss CE-2 which used the MN3007 BBD chips clocked with the MN3101chips for a very warm sounding analog chorus. So when I opened it up, there, they were, the chips and the classic JRC 4558 op-amps which I'm presuming are used in the input buffers and filters. Check it out.


 I'm really not one to wax lyrical about classic NOS chips and how they sound much better than the "stuff these days". But you know what, all of that reading about the "warmth of analog" and the search for the Holy  Grail of an op-amp chip or a germanium transistor that isn't available anymore and gives you the classic  warm sound (never mind how you play). That reading really rubs off on you, you start seeking out old pedals to see if there is any mojo to the analog gear. Of course all of this comes at heavy cost to your wallet and little improvement to your playing skills. But, I was a digital effects user and used a Zoom G2.1U admittedly not the best of the digital series and after which I moved to tube amplifiers and analog pedals, haven't looked back after that. Although I am a bedroom player and not a gigging musician so my experience may be irrelevant to you. One would have to wonder about the practicality of taking all the pedals to a gig or just taking an effects pedal that contains all the effects in one handy package.

However, I can tell that my guitar sounds versatile through a tube amplifier and not much through a solid-state. It could be the way the impedances of the pickups react with the preamplifier to give different frequency responses or something else. But the guitar does sound more alive through the tube amplifier. I wouldn't probably appropriate the same mojo to pedals though. Some pedals sound bad for sure, certain digital emulations can sound very clangy and metallic or brittle and certain analog sounds are mushy enough to feel good when in the mix. As always, it is a combination of your guitar, pedals and amplifier. I find that changing any one of these suitably give me a tone that makes me feel like I'm in love with it and inspires me to keep playing and coming up with inventive licks that I never knew I had in my fingers or in my heart.

Ideally that is the kind of tone you are searching for and I have found tones like that in my Laney Cub 8 as well as my Hartke G 10. So I won't vouch for one over the other but I would say that a tube amplifier can really bring out the sound of the guitar and make you appreciate it much more.

This is a speaker cabinet my dad bought in 1989. It has an 8 inch 20W RMS Philips driver. He bought this with the Philips AW739 cassette deck. There are two of these.

So I'd been using them with a Class AB amplifier that I bought, but then one of the speakers blew out and the other ripped at the cone circumference. So I decided there had to be another speaker to share the load of the first one. I'd bought these JBL speakers for the car but they turned out to be a little bigger than what I needed at 6.5 inches. Besides the main driver, they feature a mid-range and a titanium tweeter mounted in front of the speaker, so they are 3-way speakers with internal crossover in that sense.

Fitting the speakers in the cabinet ended up taking the longest time where I'd opened up all the planks in the cabinet and marked the circumference out on the wood only to find that my largest circular saw was about a quarter of an inch shorter on the diameter. I drilled it anyway thinking I'd file away the rest to make the hole bigger to fit. So the round cutaway was done in about 30 minutes but the filing took me about 2 months because it was incredibly slow to file them away and I wasn't able to do them evenly. The perfect tool for the job was a wood rasp but I did not have one and a combination of laziness and lack of time made sure I could never get around to a hardware store.

Finally one day, feeling really low because I had not achieved anything I felt was particularly worthwhile in a long time, I stopped at a hardware store on my way home from the institute. I asked for a rasp and was handed a file, it took me a drawing and a lot of description until they produced a rasp with nice jagged teeth which was slightly encrusted with natural corrosion from the bottom of this huge pile of files they had. It did not have a handle and it was for 50 INR, I asked for a handle and they said that would be an addition 40 INR. For the life of me I couldn't figure out why they wouldn't just sell the darn thing assembled for 90 INR. I paid up, wrapped it in a newspaper thickly and put it into my bag and made my way home.

Reached and thought I'd do it later and suddenly found myself at work widening away the hole, the rasp was much faster than the file and within 15 minutes I had filed away a quarter inch from the circumference to the circle I had marked originally for the dimensions. When I got to the end, I swapped with the file because I wanted a smoother surface. The rasp was practically extracting chips of wood at a time.

Then I marked the holes for the speaker mounting, drilled away and fit the speaker and the grille, soldered the wires in parallel to both the speakers, taking care to make sure that phase of both the speakers were accurate. Put the planks back together, tucked the cloth grille and assembled the speaker cabinet. Repeated the same for the other speaker and I was done. Time for testing!

You can see both the speakers through the cloth grille, the Philips is a paper cone and the JBL is a plastic cone. There is an additional metal grille cover that goes on top of the JBL GT6-S366, this cover prevents random knocks from breaking the mid-range,tweeter assembly which is mounted on the center of the speaker, off. There is a tiny magnetic JBL logo towards the bottom that snaps to the grille when you are done putting it together.


 
The amplifier I have is a V12 Class AB amplifier which I suspect is a chinese knockoff of the original Alpine V12 amplifier. It promises 160W RMS into 4 channels at 2 Ohms (that is about 640W RMS!). The speakers in the Philips were originally 8 Ohms, but during the repair I suspect the coils were changed to 4 Ohms, the JBL's were also rated at 4 Ohms, so I expect that in parallel configuration the resistance was 2 Ohms and I measured that with a multimeter to verify, it was correctly so.

So the V12 needs to be powered by a 12V battery and triggered with a voltage to the remote wire. I used a Corsair VS 650 SMPS and plugged in the 12V line to the V12 and connected the remote wire to +12. The amplifier turned on and I sent in the first strains of music using a Behringer Xenyx302USB plugged into my computer.

Blown away! crisp bass coming from the original 8 inch drivers along with mid-range being divided quite evenly among the two speakers. The JBL has a plastic cone compared to the stiff paper cone of the Philips. The titanium tweeters made for some sweet treble which didn't have excessive bite.

I started to get the feeling that I might not need to pull out my JBL GTX-1250 subwoofer for bass because it might just get too much. But I soon found that at low volumes I wasn't getting the thump I wanted. Playing it at higher volumes obviously disturbs parents and neighbours, not necessarily in that order.

So out came the sub-woofer from the rucksack. The sub-woofer has to be a bridged connection across Channels 3 and 4. Bridging in amplifiers is a certain topology that allows you to connect two amplifier channels in series so that you get more power out of them. The subwoofer is about 12 inches in diameter and specifies an RMS power of about 310W. It can obviously thunder but I wanted it to just to balance out the bass output at lower volumes. Which it did perfectly, kicking in at low volumes just enough to balance the bass out at the exact intensity of the mid-range and the treble.

Honestly, I'm no scientific designer of speakers or anything but these sound very good to me. They are probably not transparent and reflect my bias for the low end, but I'm happy! I also played my guitar in Direct Injection style and it was wonderful to hear how the low E string got its push from the subwoofer and the upper registers went to the mid-range and the tweeters. Chords sound clean and dry, obviously no colouration like guitar amplifiers do. I think it was a good result for all the DIY work that went into it. The speakers are mounted up on the walls in my room.

Added: 14-Sep-2015


We have new members in the family, meet the Boss SuperOverDrive SD-1 and the Mellowtone Singing Tree overdrive which is a boutique sort of pedal with very crunchy to gnarly overdrive tones that can almost be fuzzy. Also meet the Nux Time Core is a delay pedal that is sitting in that channel for delays in soloing. Strangely I hear a relay click when the Time Core is turned on which probably means that it implements True Bypass switching using a relay.