28 December 2011

Laney PSU Board draft

So... I found some perfboard kicking about in my house that happened to be the exact size (more or less a few mm) for my power supply board. I decided to work on a template to practice making a layout for the real board.

On the right is what will be the DC Filament Circuit, and on the left is the Full Wave Rectifier. The Diodes in the rectifier are spares I got a long time ago and don't fully trust, so they are in there just for an idea of how the board will end up looking.

The board should also include the bias circuit and the reference for the AC Heater Elevation. Floating the AC filament supply on a reference voltage can help a little with heater hum but in this build I'm using it mainly to keep the cathode followers in the circuit healthier for longer.

25 December 2011

Modded High Gain Soldano Style Preamp Complete

This is just a very quick update which also ties in with my new soldering iron that I got as a christmas present.

So first things first here is the new iron. It's a pretty simple 48w temperature controlled soldering iron that goes up to 430°C in 1 or 10° steps.
Now as for the amplifier heres the progress that i've made so far.

It's been populated with Vishay CCF60 high temp low tolerance resistors. These are ideal for this kind of circuit as they have a 1% tolerance and are a metal film type so they really help keep the noise floor in high gain circuits down. Also note the Panasonic power resistors, this is my first time using these but they were spec'd right and were a better price than the Xicons that I have used in the past that were on backorder.

The coupling capacitors are Mallory 150 series polyester film capacitors. These are very high quality and are a perfect balance between all that vintage mojo you hear about from the traditional mustard caps and also the clarity and edge of the Sprague Orange Drops.

The electrolytics are a mixture of Sprague Atoms & F&T axials. These are all very well spec'd and are a perfect match for the SLO circuit.

I shall be starting on the poweramp tomorrow hopefully and will also give a breakdown of that.

Merry christmas to all and if I don't post again before then I hope you have a great new year.

24 December 2011

The Laney Gut Project pt2

Progress has been a little slow... mainly due to waiting for funds and deciding on parts. Let's take a look!

So, the INGO transformers are mounted. Power Transformer, Output Transformer and Choke in place of the original transformer set. These transformers are SLO100 replicas.

The rocker switches are a green illuminated power switch and a standby switch marked to show the on/off position. I thought that was a nice touch. with all these things, it seems parts from 1986 sometimes aren't QUITE the same size as what is available now. Luckily those switches JUST about fit. The illuminated switch (unlike the old Marshall rocker switches) just need to be wired to the mains voltage and a neon lamp inside the switch will light up. On the old switches Marshall used there was a 5th pin especially for powering the bulb from a different tap on the PT. Snazzy.

As for sockets... I really like to use Belton Octal & Noval Sockets. They feel decent. This time round I got the actual Belton shields to fit the preamp sockets. This things are tough! Not the flimsy metal shields you get sometimes. They also look awesome.

The pins on the Belton octal sockets can be hard to manipulate. They won't handle much bending and shaping before they snap or tear. It's best to be careful if you want to try lining up the pins like this. If you do break a pin, it's actually pretty easy to swap in a new pin on these sockets so all won't be lost. Just get a spare socket to steal the pins off, that's my advice!

The Screen Grid Resistors in the photo (Green things) are 1K 3Watt enamel coated resistor from Vishay's Sfernice range. They are small in size for their power rating and more importantly they look good!

The 'purple' wire... ok it's not as purple as the spec sheet claimed it would be... and the black wire is silver tinned copper stranded 20AWG Teflon insulated wire. It solders really nicely and the insulation can handle really high temperatures, so no need to worry about melting it during soldering. The wire is rated for 600V. Teflon sleeve is also used on the octal socket connections. The pins are wired with 18AWG bus wire and sleeved to protect against shorts.

This is some filament wiring. The wires are twisted to reduce any noise that might be radiated from the wires themselves. I do this by trapping the wire in the chuck of a small battery powered drill. Wiring over the top of the socket rather than around the pins reduces the risk of creating a hum loop. Only two of the 4 preamp sockets are wired here... in parallel with the octal base filament pins... because the first two preamp valves will be using DC heat.

One other thing I decided to try out, was an in line filtered IEC. This is rated for 6A and should provide some filtering on the raw AC is it comes into the amp before the power transformer. I've not used one before so this will be a test.

Little Angel Chorus Build Log Part 2

I have finished populating the board using Hitano electrolytics, panasonic box film caps and one ceramic disc cap.

I chose the film caps as they provide a very clean and smooth sound which is exactly what I am aiming for with this chorus as I want it to be thick & lush. The electrolytic choice of Hitano's is my usual go to cap for pedals as they are have a very low leakage, quiet and very high quality.

The ceramic cap wasn't planned originally as they can sometimes be a bit harsh and work best in overdrive & distortion circuits but the film cap I had didn't fit the hole spacing on the board.

18 December 2011

Heavily Modified New SloClone Build

Well this started out as something else but has quickly taken a different direction due to a request.

The plan so far is to use Mallory 150 series for coupling/decoupling alongside F&T & Sprague electrolytics in the preamp with Nichicon & United Chemi Con Electrolytics in the power amp.

Voicing wise this is going to be a bit of a departure from the stock SLO voicing in that it's going to have an overall tighter feel with a fair bit of grit & grindiness in the midrange and I also plan on making the gain a but more aggressive also.

I've ordered all the electronics & hardware in and i'm discussing the chassis & headshell cosmetics currently.

Here is a picture of the SmashGuitars PCB's that I will be using in this build.

I shall update the blog with more info on this as the project progresses.

17 December 2011

Little Angel Chorus Build Log Part 1

Well I have been saying I would do this for some time now but mundane day to day things such as work, fire & floods have been getting in the way.

I was going to do it in a completely step by step fashion but decided that would be boring and take up about 100+ posts. So instead I have split it into sections.

Here we have the board populated completely with all the resistors and the opamp sockets for the NE5532 and the PT2399.

In the image that I have uploaded it shows that one resistor is mounted upright due to space requirements on the PCB making it so that it couldn't be flush with the board. I generally solder resistors that have to be mounted like this last as I populate the PCBs in component size order as this makes it far easier in the long run.

With this I am presuming that you know how to solder but if not I am planning a future pedal that has a smaller component count that I will do an entirely step by step guide.

I'm hoping that tomorrow I will have some time to do the capacitors which I will go into more depth on as there is some thought to be put into this stage as they have a bigger impact upon the final sound.

Also note I may also be posting the layout for this pedal once I get permission from the designer and may venture into offering BYOC style kits if their is enough interest.

16 December 2011

Blog Update

Hey guys this is just a quick post to let everyone know that I am still keeping up on this.

I have just been completely snowed under at work with christmas commitment & whatnot that I haven't really had much time to do anything for myself.

This weekend i'm finally going to have some time to myself and I received my Little Angel Chorus PCB's so am going to get this thing put together with a "semi" tutorial hopefully.

here's a picture too to show the excellent work done by Frequency Central who designed this circuit.

5 December 2011

NGD: Ibanez RGA7

Well this was something of an impulse buy as it was at a fantastic price that I just couldn't refuse.

I thought it would take quite a while to get used to playing a 7 string but it just happened naturally once I got over how much bigger the neck is.

These photos are stock but I have since changed the bridge pickup out to an EMG 81-7 and cut the bottom out of the battery box to accomodate the 9v battery

I shall post some clips of this over the weekend hopefully.

4 December 2011

Custom Overdrive

This is part of a project im working on that should turn out to be a metal guitarists wet dream....

A customer requested the cosmetics on this i was personally going to go for a gloss black powdercoat with silver lettering and chrome chicken heads. However i am very pleased how its turned out.

Its based around a TL082 dual opamp and has enough gain to kill a charging rhino, the clean boost also is  a bit extreme and can take your signal from unity gain at about quarter way up to gradually getting tighter and tighter going into complete saturation at the top end.

The tone control is pretty much a midrange sweep that just adds mid-high mids in.
The cut switch just boosts it a bit more and makes it cut through anything.

complete with true bypass circuitry of course with high quality solid core teflon wiring.
anyway enough rambling on heres a pic