What's the Frequency? – Will's curiosities blogged

Rusted drop link bolts on a Fiat Panda Mk2…

The anti-roll bar drop links are very close to the ground on the Fiat Panda, which means after many years and miles – the salt and moisture often seizes them completely.

Normally, to remove them you’ll hold the nut in place using an Allen wrench or mole grips, and then turn the nut using a 17mm ring spanner.

However, terrible rusting has led to me going through my encyclopedia of different methods to remove them. In no particular order, these are…

Straightforward undoing with Allen key and spanner – resulted in rounding off a small amount of the nut with no movement
Blasting it with PlusGas and waiting a while before trying to undo it manually
Using an impact wrench and a 17mm socket on the nut
Using a 600mm breaker bar and socket on the nut and mole grips on the bolt
Heating the nut up using a blowtorch
Freezing the nut using Loctite freeze spray
A combination of heating followed by rapid cooling
Welding a new nut to the end of the bolt (not tried this time)
Mimicking the impact wrench effect by using a hammer and cold chisel
Using Irwin Bolt Grip fluted sockets on the nut
Drilling the bolt from the other side, using cobalt steel bits followed by Easy-Out type screw extractors
Drilling the bolt from the other side, using carbide tipped masonary drill bits.
Angle grinding the nut and bolt
Using a Dremel-type multitool with a reinforced cutting disc attachment on the nut

After a combination of several of the above, this was my prize in freeing the old drop links

Sound City SC120R 2×12 Combo

Made in Germany, in 1986.

Budget tubescreamers construction comparison: Joyo Vintage Overdrive vs Behringer Tube Overdrive TO800

This post briefly looks at comparing two of the budget favourites when it comes to classic sounding, mid boosting overdrive pedals. In the UK, both pedals can be found around the £20 mark second hand, and both use either a 9V battery or a standard centre-negative pedal power supply. Both are built in China, with an LED to show when they are activated. I haven’t attempted to compare the sound and noise performance of these two units (there are plenty of existing sound demos on YouTube), but rather look at the construction quality, and examine factors that may sway peoples’ decisions to use them in either home recording, rehearsal or performance environments.

Both pedals are in green livery to show that they were obviously ~~ripping off~~ inspired by Ibanez / Maxon’s Tubescreamer pedals. The Behringer’s bodyshell is made from ABS plastic, whereas the Joyo is made from metal (feels light, so I am guessing some sort of zinc steel?)

Originally, both pedals had rubber on at the bottom, but I removed the one from the Joyo and added velcro for ease of pedalboard mounting. Both pedals’ casing are secured using four screws, with the Joyo’s have all four at the bottom, but the Behringer having two woodscrews at the bottom, and two small machine screws at the front of the pedal.

The thickness of the Joyo’s case can be seen in this photo, and the battery compartment is access via a plastic snap open door.

The Behringer has a more traditional BOSS style underfoot battery compartment. However, it requires two of the plastic pins to be push in and the ABS plastic “door” to be removed. This places strain on the hinges if a suitable tool couldn’t be found to push the pins in hard enough.

Comparing the switch operation of the two pedals, the Joyo uses a standard latching metal footswitch that has mounted onto the casing, with a positive click upon engagement. The Behringer however, uses a tiny PCB mounted shallow push switch, that is operated via a rubber stalk. The additional spring provides resistance against hard stamping. Neither the rubber nor the ABS tubing around the rubber itself looked particularly shock resistant.

Similarly, comparing the mounting of the potentiometers, the Joyo uses potentiometers with locking knobs, and is attached to the metal housing. The Behringer have the small bodied ones that have conductive plastic stalks. These are directly mounted onto the PCB with only the push-on knobs providing any sort of contact with the case.

Finally opening up the backs of both pedals also affirms that the Joyo, although still possessing components that are directly mounted onto the board, have tried to isolate the board itself from any sort of stresses and strains from operation and impact, by mounting parts onto the housing where necessary. The Behringer appears to utilise more surface mount components (despite having many standard sized electrolytic capacitors), with the majority of the pedal’s weight being the metal baseplate.

Opening up a Badger “Downbeat Lead” 30W Guitar Amplifier

Opening up a Johnson Blueline 50R

This arrived to me with a broken volume potentiometer (the board itself cracked which is a common problem for amplifiers with potentiometers that are PCB mounted directly and then suffer an impacted on the shaft), as well as an intermittent fault with the overdrive channel. After replacing the potentiometer with a modern Alpha one with a dust seal, and by securing some of the 5W “flameproof” power resistors, the amp sounded superb. A very nice, low(er) gain overdrive sound and a very usable EQ – coupled with the stock 12″ Alphatone speaker, I’d rate this at least as highly as the reissued Award-Session Sessionette (which had a Celestion 12″ driver as standard).

1×8 scrap wood cab

Housing a Jensen C8R speaker, for my Hotone Purple Wind, I used some scrap bits and pieces and made something rather wonky, but still sounds nice.

Jensen C8R speaker I got for Christmas one year put back into action

Not the most precise cuts I’ve ever done…

Handle scavenged from my test rig speaker “suitcase cab”

After purchasing some veil netting and corduroy style fabric from Button Boutique in Wellingborough…

Jensen speaker, rear panel and velcro fastenings

Teisco/Silvertone/Kawai style guitar repair

Pictures show the general chronological order that I decided to renovate this guitar in. Bought from a nice chap via Facebook, this is a 70s Japanese made two pickup instrument that has definitely been played and has seen better days. I very proudly went to make the whole thing functional and to try and improve it by making it able to play vaguely in tune!

Award-Session “The Punk” 100W transistor amp

On my travels when collecting up odd and repairable guitars, basses, keyboards and amps, one of the rarities encountered was a variant of the Award-Session Sessionette amplifier – namely an adapted version of the 100W bass amp they did. The combo houses a 12″ Celestion G12-75T, rated at 100W, to match the fact that the combo itself is about 90W RMS output. Like the majority of Award-Session amps, it is a solid state unit.

When I spoke to the chap who was selling the unit, he told me that he “switched it on, and it started smoking”. Naturally, my assumption was that he left it to cook and simmer first before switching it off and may have even reheated it too. There’s a fine line between it annoying and saddening me, but at the same time, it should prove to be an interesting project. When I got back and decided to open up the unit, I noticed a couple of things:-

1) The preamp unit, speaker, toroidal transformer, as well as all wires and connectors looked fine

2) The power amp board had at least one component that had died, leading to a small fire and possibly an exploded capacitor

The latter of the two meant that there was potentially acid goop and cack all over it. Upon disassembly, this is what I had seen…

Even after an inital wipe down with some rubbing alcohol, it was blatant that it was pretty much impossible to decipher some of the component values. Coupled with the fact that some of the PCB tracks had been destroyed on the underside, this caused some major issues.

Just when things didn’t look bleak enough, I noticed that I couldn’t actually get a replacement board, as they are now effectively explicitly out of production.

Still, I decided to email Award-Session anyhow to see if there were any schematics, references, clues, support that can be either provided to me whether free or purchasable. Very kindly, they came back with the schematic for the bipolar power module that at least covered some of the component details. Alongside the available SB-100 schematic, I should hopefully be able to make some sense of the power amp section that has died. That way, alongside component replacement, I should be able to point-to-point wire across the damaged track sections.

I set about trying to recouncile the diagrams with the circuit board, when it became apparent the standalone bipolar power module and the rest of the power amp were on the same board, whereas the diagram referred to specific parts.

I set about making notes of all the component values on the board, as well as cleaning off as much of the soot and remains of the incinerated resistors using ethanol as best as I could. Although it was tempting to use slightly more invasive chemicals, I couldn’t really risk removing any of the existing component markings on the board.

On the rear of the board, the already damaged tracks did not take cleaning all that well, which further reinforced the fact that I would need to do some point-to-point wiring in place of those former connections.

A little bit more cleaning was done after the remaining components had been removed. I left the MOSFETs in place as they did not appear to be impacted by the burnout (visually). I am always warying that subjecting the MOSFETs to potentially unnecessarily desoldering is an unnecessary risk, plus I wasn’t entirely sure whether replacements from RS / Mouser could be sourced for them easily.

My sense of colour isn’t brilliant and although I don’t need glasses, my eyesight is far from perfect. Rather than junking the majority of parts pulled from the board, I labelled and taped them to a piece of paper in the event I misread any of the resistor colours or capacitor codes. The black tray there were for totally fried, unidentifiable parts, as well as electrolytic capacitors that I could easily read the values from.

To be continued…

Building batten photo frame, for an A3 sized print

So, Mum wanted to know whether we can get an A3 photograph of the children and their partners together with her. I said to her, that I could do one better and I’d love to build a frame from scratch for it. So, this is what happened…

Note: Most of these photos were taken using my 33 year old BlackBerry. Occasionally, I would be stupid enough to take the EOS into the garage, but all the pics that look like they were taken using a toothbrush – that would be the BlackBerry.

Cutting the main pieces out of a single building batten

The main pieces were all made from a single piece of Wickes building batten (one of these: http://www.wickes.co.uk/cladding-batten-21x34x2400mm/invt/120942/). I love the smell of it when it is sawn, as it is basically spruce that has been roughly planed.

I used a cheap mitre box, as well as an Irwin pull saw to create the four pieces that were to be mitre joined.

Setting up my homemade router table

My router table was a very basic 3/4″ plywood board, with recess cut for an MDF insert, which in turn held my plunge router upside-down. The disadvantage of this is that the router has a dead-man’s switch system which meant that I had to clamp the switch (!!) to keep it running. My new Axminster dust extractor thingy was held in place by my homemade 100mm pipe holding jig thingy. Super simple construction meant that it wasn’t the most precise table – but the fence that I had made wasn’t too bad and I had shimmed the insert to make sure that the pieces could be fed through smoothly.

Using both the Roman Ogee bit and also the medium sized straight bit in turn, I managed to cut a dual-ogee profile onto the “fronts” of the pieces. Similar, on the back, I cut a deep enough recess using the straight bits for the perspex front, picture and backing hardboard. A block plane was set finely to clean up the recesses.

I used my freshly sharpened cheapy chisel to tidy off the flash-style lines from the edges of the Roman Ogee bit (i.e. where the bearing stops the cutting) as well as sort out any untidy bits from the planing.

Clamping and gluing

The pieces were checked for fit.

I tried a variety of different ways to securely clamp the thing together. The glue used was ordinary PVA. Although I had a corner clamp – the fact that I had made several slight mistakes meant that I was left with at least one open mitre. Instead, I tried using sash cramps in a variety of configurations and ended up settling on using the workbench dogs to pin it as well.

In the end, this was the configuration that worked for me:-

Cutting the perspex front

Thin perspex is notoriously brittle, and instead of a straightforward coping saw attack, I decided to use my engineer’s scriber and score lines across it. I also tried using a standard craft knife. In the end, the pieces were broken off, but there were some jaggies and some cracking on the edges which I ended up cutting off. Unfortunately this left me with a slightly smaller piece than I had wanted.

Gluing in the perspex

I used two-part epoxy (one of my favourite adhesives for most repair jobs) and some spring clamps to secure the perspex onto the frame.

Finishing off

Initially, a lot of the overspilled glue and other handling marks were taken off by hand using 160 grit sandpaper. I wanted to keep the ‘lightness’ of the wood, so I decided to initially apply a layer of shellac-based sanding sealer.

The sanding sealer was then smoothed down using 600 grit wet-and-dry paper, and then a very light coloured wax finish was applied. Only a single coat was put on, to avoid creating too much of a “yellowing” effect. Along with the trimmed hardboard, it looked pretty nice.

I then decided to get the photograph printed at Max Spielmann’s in Wellingborough. Terrible service, but nice Epson 12 colour LFP there.

Skipping quite a few photographs, the end result was very pleasant indeed…

Extreme Customer Service…

Spotted at Wing Yip, in Birmingham – a couple suffer a puncture and most of the staff come along and try to change the tyre. I haven’t seen service like that from most franchise garages, let alone oriental food superstores…