Kotipolttoinen

Projektikuv(i)a 2

nospam@example.com (Pekka Lehtonen) — Tue, 28 Dec 2010 20:21:18 +0200

Tankki kiinnitetty, penkille sarana tehty, keulaa madallettu ja paikalleen sovitettu, lampun kiinnike tehty, akun teline tehty. Vahvikkeita hitsailtu. Kiinnikkeitä poistettu. Pakoputkia pätkitty. Tankoa muokattu. Saumoja siistitty. Seuraavaksi purku, hiekkapuhallus ja rungon jauhemaalauus.

Habahaba.

Tonebender mk3

nospam@example.com (Pekka Lehtonen) — Sat, 18 Dec 2010 15:05:37 +0200

Slight modifications to my Tonebenderish fuzz. Put a pot in series with input. In minimum all input signal is fed to the first transistor. With high output pickups this can really drive the circuit in to deep saturation with some serious barf. At maximum it limits the current driving the first transistor. This cleans up the sound and gives a less fuzzy sound. Also dialing down the guitar volume a little bit cleans the "barf" nicely.

Projektikuvia

nospam@example.com (Pekka Lehtonen) — Thu, 25 Nov 2010 22:54:01 +0200

Penkin takaosa, akkulaatikko ja lokarinpätkä "peltivalmiina". Tankkia sovitellaan.

Profiili

Peltiä

Converting MKV to Sony Bravia compatible AVI

nospam@example.com (Pekka Lehtonen) — Fri, 29 Oct 2010 10:41:32 +0300

After extensive Googling/noodling I came up with this:

#!/bin/bash
mencoder -noidx -oac copy -ovc copy -o tmp.avi $1
ffmpeg -i tmp.avi -f avi -vcodec mpeg4 -b 1700000 -g 300 -bf 2 -vtag divx -acodec copy $1_divx.avi
rm tmp.avi

(copy that to a script file on you pc and run: "./yourscript your_video_file.mkv")

ffmepg alone did not work due to some time stamp bug. By first transferring from mkv to avi container with mencoder and then encoding to DivX with ffmpeg I finally got the video to play on my Bravia TV.

ffmpeg can be used alone but then the audio also has to be recoded:

ffmpeg -i your_input_file.mkv -f avi -vcodec mpeg4 -b 1700000 -acodec ac3 -ab 128000 -vtag divx out_divx4.avi

Using mencoder alone should also be possible but for some reason it just did not work. There was a warning about aspect ratio not been set and thus some header was not written. This probably stopped Bravia from playing the file.

If anyone has an idea how to get subtitles from mkv to the avi please let me know.

Tankki

nospam@example.com (Pekka Lehtonen) — Sat, 09 Oct 2010 13:17:30 +0300

Simson - Suhl

Nätti kuin sika pienenä.

My Nokia Booklet battle part 3 - Harddrive issues

nospam@example.com (Matti Leino) — Tue, 14 Sep 2010 09:00:36 +0300

I'm starting to feel a bit frustrated with Booklet. It's basically very nice piece of hardware, but Poulsbo is so big failure in so many ways. Fucked up beyond any repair, you could say. But it may be possible to live with that anyway...

Anyway, yesterday I started to investigate this clicking sound I heard. It was obviously HD spindown. It made every 10-15 sec, basicly no matter what I did. Not very nice. Looking at 'sudo smartctl -a /dev/sda|grep 'Load_Cycle_Count'' showed that value is increasing like 1000 per day. Not very nice in any way.

First, I tried 'sudo hdparm -B 254 /dev/sda', without any big success. Then I tried 'sudo hdparm -B 255 /dev/sda' (to disable APM totally), without any success. I also tried to set big standby timeout ('sudo hdparm -S 241 /dev/sda'), that wasn't success either.

I couldn't find easily any reasonable reasons for spindown. I tried to disable them via Gnome's Power Management, without any success again. There wasn't any laptop-mode's set, so that couldn't be it. I then found one page, http://techjamaica.com/forums/showthread.php?t=90496, which had some hints. Well, I hadn't had any luck with more popular ways, so I tried these instructions.

sudo apt-get install laptop-mode-utils

/etc/default/acpi-support:
Add "ENABLE_LAPTOP_MODE=true" in the end of file

/etc/laptop-mode/laptop-mode.conf:
Change line "HD=..." to "HD=/dev/sda"
Change line "BATT_HD_POWERMGMT=..." to "BATT_HD_POWERMGMT="254"

sudo echo 5 > /proc/sys/vm/laptop_mode
/etc/init.d/laptop-mode restart

According to linked website, that should do the trick. It didn't, even after rebooting, I heard clicks every 10-15 secs. I then started to play more with laptop-mode, I tweaked it a bit more

/etc/laptop-mode/conf.d/intel-hda-powersafe.conf
Change line "INTEL_HDA_DEVICE_TIMEOUT=..." to "INTEL_HDA_DEVICE_TIMEOUT=1800"
Change line "INTEL_HDA_DEVICE_CONTROLLER=..." to "INTEL_HDA_DEVICE_CONTROLLER=0"

/etc/sysctl.conf:
Add "vm.dirty_writeback_centisecs=1500" in the end of file
Add "vm.laptop_mode=5" in the end of file

At this point, I decided to go to sleep, as it was way too night for hacking. I still could hear the clicks, also I got yet-another-kernel-oops, which looked to be related to filesystem/ext4. I already thought to revert back to 9.10, as Ubuntu's wiki says that it should be perfectly supported.

Big surprise was today, when I powered Booklet up, and I haven't heard any clicks so far. I mean, I have had it open for few hours now, and Load_Cycle_Count has increased just by one or two. I'll definately will be following this.

XS650 projekti

nospam@example.com (Pekka Lehtonen) — Wed, 08 Sep 2010 20:18:33 +0300

30 vuotisen taiteilijauran kunniaksi päätin ostaa 30 vuotta vanhan moottoripyörän. Yamaha XS650:n eli tuttavallisemmin Jytä Jammun tahi Jytärin. Kunnostus/rakenteluprojektia pukkaa. Lähtötilanne oli kutakuinkin tämä:

Yamaha XS650 SE US custom, vm. 1980

Sittemmin mopo on purettu osiin ja projekti jatkuu kutakuinkin seuraavin vaihein:

Hiekkapuhallus + jauhemaalaus:
- T-palat + tangon pidikkeet yms
- Keulan alaputket
- Vanteet
- Jalkatapit
- Runko
- Takaswingi

Rakentelua (/muutoksia):
- Ketjusuoja
- Akku/sähkökotelo
- Satula
- Takalokari
- Mummorauta
- Jalkatapit
- Lamppu
- Mittarit
- Sähköt
- Keulan lyhennys
- Starttimootorin poisto
- Rungon korjailut ja siistimiset

Muuta:
- Uusi ohjaustanko
- Uudet sähköt
- Uusi tankki
- Jarruremontti

Eiköhän siinä ole talveksi tarpeeksi puuhaa.

My Nokia Booklet battle part 2 - Internal GPS

nospam@example.com (Matti Leino) — Tue, 07 Sep 2010 13:52:54 +0300

So, I wanted to get internal (A)GPS working. Too bad, it didn't have much documentation, at least directly Linux-related. Instead, instructions how to get it working in Windows can be found from http://discussions.europe.nokia.com/t5/Mini-Laptops/Can-I-use-GPS-without-have-3G-data-plan/m-p/594454. Problem was what are COM4/5 equivalents in Linux. After trying, I found that /dev/ttyHS4 is GPS control channel, and /dev/ttyHS1 actual GPS data channel.

It really has been **years** when I last used minicom other terminal programs. Thanks to my colleague, Pablo, who pointed me to use good old kermit, ckermit to be more precise, and try that. I got, yea! This is how I did it:

C-Kermit>set line /dev/ttyHS4
C-Kermit>set carrier-watch off
(C-Kermit>set speed 115200
/dev/ttyHS4, 115200 bps
C-Kermit>c
Connecting to /dev/ttyHS4, speed 115200
Escape character: Ctrl-\ (ASCII 28, FS): enabled
Type the escape character followed by C to get back,
or followed by ? to see other options.
----------------------------------------------------
T S7=45 S0=0 L1 V1 X4 &c1 E1 Q0
OK
ATZ
OK
AT_OGPS=2

OK

After AT_OGPS=2, second kermit-instance, connected to /dev/ttyHS1, started to output raw NMEA data. Very good. Now it's time for some kermit scripts:

~/bin/gps_on.sh:
#!/usr/bin/kermit

def port /dev/ttyHS4
def speed 115200
def carrier-watch off

set port \m(port)
if fail exit 1 Can't open \m(port)
set speed \m(speed)
set carrier-watch \m(carrier-watch)

output AT_OGPSP=7,2\13
input 3 OK

output AT_OGPSCONT=1,"IP","prointernet"\13
input 3 OK

output AT_OGPSLS=1, "http://supl.nokia.com"
input 3 OK

output AT_OGPS=2
input 3 OK

exit

For turning GPS off:

~/bin/gps_off.sh:
#!/usr/bin/kermit

def port /dev/ttyHS4
def speed 115200
def carrier-watch off

set port \m(port)
if fail exit 1 Can't open \m(port)
set speed \m(speed)
set carrier-watch \m(carrier-watch)

output AT_OGPS=0\13
INPUT 3 OK

exit

Still maybe some checking would be needed, to see if it really uses assisted GPS instead of "plain" GPS. It really doesn't matter so much, though assisted is much faster in locating you initially.

Next I'll have write scripts for monitoring GPS status, and then find some suitable navigation sw.

EDIT: I originally said ttyHS0 was data channel, while it really is ttyHS1, sorry about that.

My Nokia Booklet 3G / Ubuntu battle

nospam@example.com (Matti Leino) — Mon, 06 Sep 2010 08:17:59 +0300

I should have known better. At least two of my friends warned me that changing my Samsung NC10 to Nokia Booklet 3G is bad idea. At least when considering installing Ubuntu on it. What the heck, I have had battles before, I used to have some nice nights tweaking my desktop with older Nvidia and dualhead, Nvidia's legacy drivers and incompatible xorg ABI.

So, I got it running. I used 10.04.1 alternate install cd, cause I needed encryption also. First issue, at least for me, is that I could get only flashdrives created with Ubuntu's usb-creator-gtk working. I tried Unetbootin, I tried Pendrive Linux's usb creator. Latter didn't even boot, one created with Unetbootin didn't know how to install files from flashdrive, instead tried netinstall. Which didn't work for me, since Booklet doesn't have wired lan, and wlan doesn't work yet in installation. Good start! Problem was that I don't have any Ubuntu machines, since I normally use Debian. So I had to 1. Burn Ubuntu live-cd 2. Boot one of my laptops from it 3. Copy installation .iso to one flashdrive (since cd-live-laptop has only few hundred meg's free space) 4. Create install-flashdrive from another flashdrive

Ok, so ahead with installation. Nothing special there. It was too easy, it just worked. First boot, X resolution sucked. Known issue due to the buggy Poulsbo chipset.

First, I followed instructions from https://wiki.ubuntu.com/HardwareSupportComponentsVideoCardsPoulsbo:

sudo add-apt-repository ppa:gma500/ppa && sudo apt-get update
sudo apt-get install poulsbo-driver-2d poulsbo-driver-3d poulsbo-config

And rebooted. Now also native resolution worked like a charm. Bad thing is that with Poulsbo-driver, all kinds of power management issues comes, so following same page, I:

sudo apt-get --purge remove vbetool && sudo apt-get install uswsusp

And rebooted. Now I could get suspend working with 's2ram --force'. Too bad that Ubuntu/GNOME doesn't provide directly options to change default suspend-command. So:
1. I replaced default pm-suspend with s2ram: 'sudo mv /usr/sbin/pm-suspend /usr/sbin/pm-suspend-old && sudo sudo nano /usr/sbin/pm-suspend'

/usr/sbin/pm-suspend:
#!/bin/sh
/usr/sbin/s2ram --force

2. Granted sudo-rights with NOPASSWD-option to admin-group users with 'visudo':

%admin ALL=NOPASSWD: /usr/sbin/s2ram

3. Created shortcut key ctrl-alt-p to execute '/usr/sbin/s2ram --force'
4. Changed s2ram as default suspend-command.

/etc/pm/config.d/00sleep_module:
SLEEP_MODULE="uswsusp"

/etc/pm/config.d/defaults:
S2RAM_OPTIONS="--force"

Then I played a bit with Power Management options in System - Preferences - Power Management, just to check that there's no "hibernate" anywhere, since I haven't tested '/usr/sbin/s2disk' (Suspend to Disk) yet. That's the next part.

Also, I noticed that:
1. Flash's can't be played fullscreen, only white screen shows. Not a big issues though.
2. Thunderbird can't be used. If installed from repositories, it shows blank menus & co. It's described at least here: https://bugs.launchpad.net/ubuntu/+source/thunderbird/+bug/564011. Installing Thunderbird directly from mozilla.com did worked. I did:

tar xjf thunderbird.tar.bz2
mv thunderbird/ /usr/local/
ln -s /usr/local/thunderbird/thunderbird-bin /usr/local/bin/thunderbird
export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/thunderbird/

Unfortunately, I got at least one kerneloop with thunderbird:

Sep 4 23:03:03 nauris kernel: [ 5381.598586] BUG: unable to handle kernel paging request at f76f4000
Sep 4 23:03:03 nauris kernel: [ 5381.598607] IP: [] prep_new_page+0xe7/0x170
Sep 4 23:03:03 nauris kernel: [ 5381.598630] *pde = 00007067 *pte = 00002c00
Sep 4 23:03:03 nauris kernel: [ 5381.598643] Oops: 0002 [#1] SMP
Sep 4 23:03:03 nauris kernel: [ 5381.598653] last sysfs file: /sys/devices/LNXSYSTM:00/LNXSYBUS:00/PNP0A08:00/device:1f/PNP0C0A:00/power_supply/BAT1/voltage_now
Sep 4 23:03:03 nauris kernel: [ 5381.598665] Modules linked in: fbcon tileblit font bitblit softcursor psb drm_psb agpgart i2c_algo_bit binfmt_misc rfcomm ppdev sco bridge stp bnep l2cap joydev snd_hda_codec_intelhdmi snd_hda_codec_realtek arc4 snd_hda_intel snd_hda_codec snd_hwdep snd_pcm_oss snd_mixer_oss snd_pcm snd_seq_dummy snd_seq_oss snd_seq_midi snd_rawmidi snd_seq_midi_event snd_seq snd_timer snd_seq_device ath9k snd mac80211 ath uvcvideo cfg80211 psmouse lp parport soundcore sdhci_pci sdhci videodev v4l1_compat hso serio_raw btusb bluetooth i2c_isch snd_page_alloc led_class sha256_generic aes_i586 aes_generic dm_crypt usbhid hid video output pata_sch
Sep 4 23:03:03 nauris kernel: [ 5381.598825]
Sep 4 23:03:03 nauris kernel: [ 5381.598836] Pid: 3835, comm: thunderbird Not tainted (2.6.32-24-generic #42-Ubuntu) Nokia Booklet 3G
Sep 4 23:03:03 nauris kernel: [ 5381.598847] EIP: 0060:[] EFLAGS: 00010246 CPU: 1
Sep 4 23:03:03 nauris kernel: [ 5381.598857] EIP is at prep_new_page+0xe7/0x170
Sep 4 23:03:03 nauris kernel: [ 5381.598866] EAX: 00000000 EBX: f76f4000 ECX: 00000400 EDX: 0000000Sep 4 23:07:48 nauris kernel: imklog 4.2.0, log source = /proc/kmsg started.

... So I swithced to claws-mail....

EDIT
Seems that Thunderbird-issue (well, rendering-part, not the kerneloops-part) is described already here: http://ubuntuforums.org/showpost.php?p=9600101&postcount=1467

TODO
- ~~Get mplayer working~~ - Got it working by simply running this script: http://kanotix.com/files/fix/mplayer-vaapi-latest.txt
- ~~Get (A)GPS working~~ - See part II
- Test s2disk
- Check if that another thunderbird works or not.

OptiVibe Mirco - a simple optical vibe/chorus/phaser/whatever

nospam@example.com (Pekka Lehtonen) — Tue, 31 Aug 2010 10:17:50 +0300

This is a simple 2-stage optical vibe-effect for guitar. I've wanted one for quite some time and now I built it. Mellow and subtle. Not "over the top". This "design" is an adaptation of various Internet sources. Hope you find it usefull. I did. Here are schematics and a VERO-board layout (in EAGLE format): optivibe_micro.sch, optivibe_micro.brd

Schematic with comments

Guitar speaker cabinet with Eminence Delta Pro 12A

nospam@example.com (Pekka Lehtonen) — Sun, 13 Jun 2010 21:35:11 +0300

A reflex cab with a pro audio speaker that is said to be close to the legendary Electro Voice speakers. The cab has approx 48litre internal volume. It is made from 15mm pine plywood. Covered with black felt. It is tuned to approx. 70Hz with 100mm diameter 30mm long tube.

DD101 and the EDP12A cab

The port has changed to bigger and shorter after the pic was taken.

I'm still testing and getting used to the sound but initially it appears very neutral and un-colored with big bottom. Still needs steel corners and grille.

3-knob Tone Control For Guitar And Bass Amps (a.k.a The TMS Stack)

nospam@example.com (Pekka Lehtonen) — Fri, 19 Mar 2010 17:46:06 +0200

I wanted a "different" tone control for my Low Gain Amp. By combining modified BigMuffPI tone with modified Marshall bass amp MID control I got this:

Sounds nice. Gives bass/treble tilt and variable mid scoop. For nearly flat response (3dB mid scoop at 540Hz) set TONE to 1 o'clock and MID to full value. Change C23 to 2.2n for less than 1dB scoop. If you try this in your amp please let me know how it works for you.

Pekka

DD101 - The Low Gain Tube Amp

nospam@example.com (Pekka Lehtonen) — Thu, 11 Mar 2010 09:40:17 +0200

I got hold of an old PA/central radio amp few years ago. I wrote something about it to the old KP here. The amp was not working at the time but had some nice parts: Four EL34's, EF86 and ECC83 in preamp and huge transformers. Also a big and "good looking" (but a little bent) chassis.

Apparently the amp was made in Finland in 50's or 60's. Now the amp got a new life as a low gain (bass)guitar amp. It features two EL34 output tubes, 12AX7 DC-coupled PI and 12AX7 Preamp with Tilt. Mid and Volume controls.

Original condition

Dis-assembly

I traced out the schematic of the amp and decided that I would not use it as it is. I decided to dis-assemble everything. Most electronic parts went to thrash. Old can electrolytic caps and scary looking mains connectors had to go. Actually I only kept the tube sockets and two red lamps on the front panel. After removing all parts I removed most of the old paint from the chassis.

Finished amp

Output transformer

The OT was huge. It had UL-taps in the primary (actually 57% instead of 43%). The output transformer secondary was for 100V line. I disassembled the transformer core and wound 10 turns of wire over the existing windings. Then I fed a 1kHz signal to this 10 turn coil and measured voltages from all coils. I found that primary had approx. 2000 turns of wire. I calculated secondaries so that I got approx. 6kOhms primary impedance. 76turns for the 8ohm output. I was supposed to measure the tranny but did not have the patience for that. I assembled it to the chassis and wired to the circuit.

Hand wound secondary...

Chassis

The chassis is a true classic. Huge and ugly. Bent and scratched. Originally the chassis was painted with blue hammer-tone but someone had painted it over with some white paint. Latex or oil based paint used to paint interior walls in houses or something. I wanted to keep something original in the amp so I painted the chassis with something that claimed to be "Black Hammertone" in a spray can. Well, not quite. It is actually gray and does not look like hammertone. You cant win every time... I did not have to drill any new holes except for the new IEC socket.

Schematic

Schematic 1.5

Schematic 1.3

UPDATE 13.6.2010: Schematic rev. 1.5. With new PI, PPIMV and subsonic filter before poweramp.

UPDATE 21.3.2010: New schematic uploaded.

UPDATE 15.3.2010: Now the amp is pentode connected with NFB to PI. Preamp tubes changed to 12ax7 for more gain. Schematic soon. New Mid controll also coming up.

Sound

Big and clean

Old info: The amp has really low gain and huge headroom. I tried to push the input stage to distort with a booster but 10Vpp signal was not enough for that... The tone control works good at least with a guitar. Nice "Tilt" control with some mid scoop adjustment. Tone control is a version of the Big Muff PI tone. It works nice but I would like a better control for the mid frequencies and may change this in the future. Seems to work great with distortion pedals.

Problems

Due to the 57% UL taps I only got approx 20W of clean output. I was hoping to get over 30W clean and near 40W full distortion. This is a setback. Now I need to add second pair of tubes or change to pentode circuit. That sucks because with pentode I have to use feedback and post PI master volume is not optimal with it. UPDATE 13.6.2010: I have now changed the amp to fixed bias with NFB and PPIMV and it seems to work better than expected. About 60W at full clipping. Maybe more. Definitely more if a 4 ohm cab is plugged to the 8 ohm output.

Pekka

Tonebender MK2

nospam@example.com (Pekka Lehtonen) — Wed, 17 Feb 2010 20:20:31 +0200

Samaan purkkiin aikaisemmin esitellyn Torso Fuzz 2:n kanssa päätyi tämä Tonebender-variantti. Paras pörinä jota olen koskaan kuullut. Tästä ei irtoa "kevytrosoa" edes yrittämällä. Kaulamikki käyttöön ja soittamaan sooloa Wolfmotherin Love Trainiin. Trankkuina samat OC140:t kuin Torsossa. Muutkin sopinevat. Biasointia voi joutua säätämään.

Vero-levy layout

Pekka

6V6GTA PP guitar amp - Finally done?

nospam@example.com (Pekka Lehtonen) — Wed, 27 Jan 2010 23:32:05 +0200

The official version 1.0 (after four years in the making...)

Ok. This one in English. I've been building this amp for four years now. Last two years I was just happy actually playing guitar through it but then I decided to change the power tubes. From EL84 to 6V6GTA. Last month or so has gone in rebuilding the amp. I was only supposed to do quick rebuild on the power amp. Eventually I ended rebuilding the entire thing and actually went through several different versions before settling with this one. Also built a new cabinet.

The topology of the amp is quite traditional. 3 gain stages, cathode follower, PI and pentode Push-Pull power amp. Three 12AX7's and two 6V6GTA's (NOS RCA). The amp is now basically AX84 SEL preamp with 20W core power amp. The preamp has been modified to my taste. The power amp and PI was built from components I had available. This is the first time I have implemented Presence control. The schematic shows the current state of the amp.

New cabinet pictured against nice pink backdrop

Features and specs:

2 x 12AX7 preamp
6V6GTA (RCA NOS) PP power amp with 12AX7 PI
5AR4 rectifier tube
UralTone power transformer
Hammond Mfg 125E output transformer
Approx. 20W output power at full tilt
Gain, Bass, Treble, Middle, Presence and Volume controls
Two switches for fine tuning the bass in the first gain stage
3 stage preamp with cathode follower
Traditional tonestack

I think I'm happy with the amp now. Had a lo of issues in the rebuild. The old preamp just did not work with the first version of the new power amp. The power amp also oscillated at 30kHz is volume was set too high. I got the oscillation under control but the sound still was not right. Then I ripped out the entire old amp and rebuild it. First the PA, then preamp and then PI. Some fine tuning in the preamp and now things seem ok. Enough gain, cleans up ok from guitar volume. Not too bright but also not "muffled". No strange noises, crackles, hisses or buzzes. Not even at full tilt. The only thing that bothers me is that the Presence control is effective only in the last third of the rotation. Maybe I'll look into it some day...

Sound samples may not become available sometime in distant future.

EDIT 6.2.2010 - Added an adjustable feedback. Turned down the NFB and to my great surprise the sound opened up and really started to growl. I guess it is more Marshall now. The presence does not do much without NFB...

EDIT 9.2.2010 - Bias adjustments, 560ohm G" resistor and JCM800 style 2nd stage with switch. 270nF Presence cap.

Pekka