Plexi SE demo!

Demo of my plexi SE.

already biased to a closer plate dissipation value. resulting in a louder overall volume. no really signifacant tone changes noticed though.

all are recorded using youtube's online webcam recorder with a cheap mic.

Plexi Jr Build.... It's alive!!!!!!!!!!!

Plexi Jr Build - Day 1

So, it took almost two whole day to finish it all up! but for the first fire up, smokes came out of the Power transformer!!!!!! damn!

Troubleshoot it with the help of Razi for a couple of hours until i realise that the rectifier used was not compatible with the PT. took out two of the 1N4007 off the ground and no more smoke...

but wait! the tube won't light up! tried bypassing those 100R (R1 & R2), and also no connection between pwr tube's pin 8 and filamen lines, but still to no avail!

turns out that connection of pin 8 and filament lines was suppose to act as an artificial center tap, but my PT already has a center tap for the low voltage 2ndary!

but that wasn't the problem though....

The problem was simple. I didn't forced the tube into its sockets hard enough! I had to go to Razi's house to know about this! haha

How does it sound now? couldn't really say much now. too early to tell much. caps havn't burnt in yet and all..

but lots of bottom end for sure. the TMB does make the tonal possibilites wide. overall volume output is not that loud though.

but the gain! it does has a lot of gain. but won't be able to reach into metal territory though without any pedals. great classic rock (say led zep) tones though!

with my modded TS9 in front, it really is a rock monster! not really metal territory yet, but for those modern rock tone, it's great!

so i pushed it with TS9, now i push it harder with my Dr Boogie! with it's gain set below 9 o'clock, the amp turned into a metal monster! Muahahaha! lots of gain with bottom end that the Plexi Jr has! Krraaannnnkkk!!!!!!!

however, the only problem now is the bias. the stated schematic cathode resistor gives too cold of a bias (around 10 watt instead of 14watt plate dissipation voltage). this would probably be because my PT's HV 2ndary is 220V while in the schem is260V.

probably it'll sound better after biased right?

Soundclips/vidz would be up when i hav the time. for now, below are some pictures!

PLEXI Jr. Build -DAY 1

I've mod pedals, then mod my tube amp, and then build pedals. a quite addictive hobby i must admit.. so, next?

I'm building an amp! Been playing with that idea in my head for quite a while now. Hi-Octane was one of my target. but then i found... Plexi SE!

It was designed by the guys at sewatt.com (initiated by z_stingray) and was intended to be as a drop replacement for Epiphone Valve junior. The Plexi SE pcb can be bought at guitar amplifier pcbs website.

But the board cost USD30, thats RM100+ after conversion n shipping! so, i designed a layout of the schematic, in a PTP turreted style. all the ground would go on one line and grounded one point on the chasis.

This is the layout i've done. btw, its not gonna be build on a stripboard as shown, its just that software i use for my convinience. those red dots (cut tracks symbol) is the turret.

Components are bought from Jalan Pasar and from Nik Azam of ceriatone. chasis and transformers are from Razi of rseaudio.

as of now, i've already soldered most of the part on the turret board except about 4 parts coz i bought wrong values of resistors! and also, i have to drill some of the holes on the chassis to increase those hole sizes.

Below are some pics!

package unpacked!

Drawn up layout on the board as markings when drilling (forgot to took a picture of it after drilled an turreted though)

turret board 90% soldered up

full pic with the chassis, output transformers, and power transformers

In the night shall fall

Darkness creeps
music soothing in the air
lost in the waves of harmonics
finding way through the darkness
i will not fall
holes that i did not see
this darkness holds
the light that darken
the night that lights up
shall i go through?
still
hold still in the state of mind
steady state holding still the voices
would they ever be silenced?
controlled to the very least of comfort?
slave is what they have made me be...

Me

Me..
What am i?
Who am i?
what do i wanna be?
direction of my life?
planned lots of things in ma mind
but did so little
thought a lot
never did enuff
dream high
but nothing in reality

discipline and determination
perseverance and consistency
focus and concentration
all of which i should have
all of what i thought of i should be
excuses by excuses
i lay out on me

when would the road really be taken
when would i would wake from this?

only me
only I
Hadi Hasannudin
could answer that

2.06 a.m.

Hungry at 2.06 am,
sitting on my bed infront of this,
sinking inside the soothing music of my collection,
need i say more?

the season is in,
as the flu 'flu' around hoping from one to another,
infecting others in sight or upon touch,
annoying as it is,
distracting normal life and its activities.

sleepy eyes,
blurry and blurry it gets,
but still
scribbling away by pressing
this written words of no directions
hoping to go somewhere
but hopeless without plan n direction

these are the words
that hav no meaning or direction
and it will
it will
it will
STOP!

Dr Boogey build - Finished!!!

Dr Boogey build (Day 1)

Dr Boogey Build (Day 2)

Finally, the beast is alive!!!! After weeks of debugging, i finally succeed! Right after all the parts arrived, i wired everything up. Thought quite a lot about positioning of the knobs though when the drilling the enclosure.

The problem started right away after everything was wired up. Got sound when bypassed (using true bypass) but nothing when enganged! Damn! Checked all the solder and wiring, everything looked ok. Then, i took the jfet's reading and post it at diystompboxes.com forum. The guys told me that the voltages of my Q1 and Q2 (the jfet's) weren't right. At Q1 the voltages were nearly the same for all feet (D, S and G) while at Q2, there's no voltage at S while G shows high voltages reading. I replaced the Q1 with an j201 laying around (used for the MT2 mod but took it out) but still nothing. Then decided to resolder the components around Q1 coz my soldering job there was f****ng bad! and walla! there's sound coming out of the box... but DAMN it was ugly! very fizzy and thin!

Asked again at the forum and the guys suggested that it was the Q2 that might caused it. So i ordered up some j201's from farnell with sets of sockets too! See, as explained by ultraman_cosmo (from jamtank.net), jfets are very sensitive to heat. so, by using socket, i won't worry bout frying up the j201. and i can easily swaps the jfets coz apparently, each jfet (even same type) can affect the end sound!

Then, all soldered up, setting the drain voltages of Q1, Q2, Q3 and Q4 to 4.5v, i fired it up! And the beast; Dr Boogey is alive!!!!!

The tone? fat sounding distortion with lots of balls! haha. suprisingly very quiet though. but still need some jfet biasing to be done to really nail the tone that i want. However, recoded a clip using my digital camera. It sounds kinda 'tubey' though the clips but can get you the rough idea.

Here's some pictures 1st..

the workstation!

Gut view

Another gut view

The beast itself.... Dr Boogey!

Last but not least, the demo!

of graduations, MEng and BEng...

Damn, i wish i could be there watching my frens of Nottingham University graduated juz now. but some unforseen circumstances wouldn't let me. Only got to watch the pictures taken by Nik Izzat.

So, they graduated. They chose to end after 3 years with a Bachelor Degree. and i still have one more year to go to straightly graduate to Master of Engineering. am i doing the right thing here? how big of advantage am i getting? questions been asking to myself for quite a while. I guess we'll juz wait and see.

the status of this British system of MEng is somewhat still blurry. I heard, JPA only looks at it as a degree coz its an undergraduated course; direct 4 years without graduating 1st as a 'Bachelor'. if so, how about British's system of BEng? a lower degree? same level?

Board of Engineers Malaysia (BEM) only accredited 4 years of MEng from university of Nottingham. According to the BEM's website, this means that only through MEng (for University of Nottingham), the graduated students can register with BEM as a 'Graduate Engineer'. The BEM justify it by saying that students must go through 4 years of engineering programme for 'em to be qualified to register as 'Graduate Engineer'. Every other BEng programmes in other local University (which has a duration of 4 years) is accredited and the graduate can register as 'Graduate Engineer'. This is a list from BEM's website.
http://www.bem.org.my/v3/pdf/listofaccreditedprogrammes.pdf

What does this say then to my fellow frens who juz graduated with BEng from University of Nottingham? I'm not sure but I certainly haven't heard my seniors has a hard time finding job because of that technicality. One even earning over RM20k a month working at Schlumbeger with juz a BEng in Mechanical Engineering.

So, what's the difference actually? Asked around at the UNiM's career fair some months ago, all (Shell, Cameron (oil&gas), Sime Darby) said that they do differentiate MEng and BEng. mostly with a higher salary for MEng. guess, to really know it, i juz have to look at my seniors who graduated with MEng.

Btw, below is an explaination by Dr Stewart McWilliam, director of studies for Mechanical Engineering about MEng/BEng.
________________________________________________________

Dear Hadi,

BEng (Bachelor of Engineering) and MEng (Master of Engineering) are both undergraduate courses.

MSc (Master of Science) is a postgraduate course.

The BEng and MEng Mechanical Engineering courses are accredited by the Institution of Mechanical Engineering (IMechE). This means that the courses are recognised by the Engineering Council in the UK. The MEng is the preferred route to becoming a Professional Engineer – in the UK a Professional Engineer is called a Chartered Engineer. A student with a BEng qualification needs to study to a higher level (possibly an MSc) before they are eligible to apply to become a Chartered/Professional Engineer.

In Malaysia only 4 year MEng courses are accredited by the Board of Engineers Malaysia (BEM). If you wish to be a professional engineer in Malaysia it is advisable to take the MEng. The Malaysia Campus had an accreditation visit by the BEM approx 3 weeks ago. As yet we have not recieved the final verdict, but we are hopeful that the Mechanical Engineering MEng course will be accredited by BEM.

In the UK we offer an MSc in Mechanical Engineering. Currently we do not offer an MSc at the Malaysia campus. The UK MSc offers students the possibility of upgrading their BEng qualification for the purposes of becoming a Chartered Engineer. Many of the modules studied on the MSc are identical to those offered at the Malaysia campus. The majority of modules on the MSc are at level 4 (MM 4 CFD is a level 4 module). The MSc is a full year course starting in September and finishing in August, involving 180 credits, 60 of which are for an individual project. In contrast, the 4th year of the MEng is from September to June and involves only 120 credits. A significant difference is that the MEng involves a large Group Development Project (40 credits). This project is design related involving writing a business plan, conceptual design, design evolution, proof of concept, and possibly manufacturing a prototype.

In summary the MEng is more focused on the needs of engineering industry than the MSc, whilst the MSc is used to enable a BEng student to study to the required higher level to become a Chartered/Professional Engineer. Ultimately the choice is yours. If you are intending to embark on a career in industry my advice would be to take the MEng. Alternatively you could take a BEng and then an MSc. One final point is that you should check the requirements in your country for becoming a Professional engineer, as this may help you decide.

I hope this is helpful,

Regards,

Stewart

Director of Studies

Faculty of Engineering

Department of Mechanical, Materials and Manufacturing Engineering

________________________________________________________________________________________

Anyhow, in the BEM's list of accredited engineering programmes in M'sia, MEng of Mechanical Engineering isn't there. Their accreditation team was in UNiM in May for evaluation. Hope that everything goes well and the MEng of Mechanical Engineering will be in the list soon.

Dr Boogey build (Day 2)

Dr Boogey build (Day 1)

Well, it's not actually the 2nd day, but wut the hell. Soldered all the components on the board already! just need wiring up the power jacks, in and out jacks, pots, and switch.

Went to Jalan Pasar on Monday (6/7/09) to buy the remaining parts and straight away heat up my soldering iron after reach home! but damn, dunno why my iron suddenly wasn't hot enough! hardly can solder anything. so i rush to the nearest hardware store for a new soldering iron. but damn, that iron was useless. very hard to solder up things. i was sooooo pissed then!

but then, i decided to give the old iron a try. Wallla! all metls easily and soldering on that veroboard seems very easy! Long story short, last nite (wednesday morning) at around 4 am, i finished up soldering!

checked all the continuity, fixed whatever wasn't connected that was supposed to be. and cut all the remaining parts' legs. and below is some pictures!

Under the board before cutting the legs

Legs cut!

Above of the board after all soldered up!

Dr Boogie build (Day 1)

As an intro, Mesa Boogie Dual Rectifier is a very well known amp for its brutal and crushing distortion that's very sinonim in the world of Metal music scene. but the price is however ridiculously pricey especially here in Msia; >RM10k.

So, i decided to build this Dual rectifier emulator pedal called Dr. Boogie which was designed by a guy called Electritab from diystompbox.com forum. Below is the perfboard schematic of it which is based on the revised circuit by gaussmarkov.



So, finally the parts came today (saturday, 4/7/09). and i started building it just now. however, what i did was only putting the components on the perfboard base on the schematic above. Soldering will be done later coz there's still missing parts. gotta go to Jalan Pasar to get 'em.

the present work