18 November 2006

Class A MOSFET Amplifier

Another one of Mark's projects has been added to the DIY Audio Projects web site. This time, Mark has put together a very simple MOSFET amplifier that he has fashioned after a single-ended (SE) tube amplifier.

DIY Class A MOSFET Amplifier
The amplifier uses a single MOSFET and the results are a very simple Class A SE amplifier with a low parts count. As with all of Mark's projects, the enclosure work is top notch.

 Single Ended Class A MOSFET Amplifier
For more information and photographs about this project, see Mark's DIY 2SK1058 Single Ended MOSFET Amplifier Project page.

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What's Playing: Red Rider - Walking the Fine Line

14 November 2006

Alex's build of the Fostex FE127E Sealed Bipole

A while back I finished up a DIY Sealed Tower Loudspeaker project using the Fostex FE127E driver. A short time later, I was contacted by Alex in the Philippines who told me that he was constructing this project.

DIY FE127E Speaker Project
The above picture is Alex's build of the DIY Sealed Bipole Speaker Project using the Fostex FE127E. Alex did a great job constructing the enclosure using MDF for the baffles and solid Narra for the sides. I was very pleased when Alex sent me pictures of his finished project and his positive comments regarding how nice these speakers sound.

For more pictures, see Alex's build log of the DIY Fostex FE127E Sealed Bipole Speaker Project.

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What's Playing: George Harrison - Cloud Nine

10 November 2006

A Case for the K-12M Tube Amplifier

This is Mark's build of the inexpensive and popular S-5 Electronics K-12M Tube Amplifier Kit.

S-5 Electronics K-12 Tube Amplifier KitActually, Mark has built three of these fantastic sounding tube amplifier kits! Mark has experimented quite a bit with these kits and his modifications include snubbers, a beefed up power supply, an upgraded power transformers and Hammond output transformers. I am always impressed with Mark's enclosure skills and look forward to seeing more of his diy audio projects.

For more information about these inexpensive tube amplifier kits, see: S-5 Electronics Tube Amplifier Kits.

Other S-5 Electronics Tube Amplifier Kits:

What's Playing: The Velvet Underground - Sweet Jane

07 November 2006


Originally Posted: 5 November 2006

DIY Audio Projects by Gio has made the move to it's new home ... diyAudioProjects.com. New site content includes a recent project of mine, a DIY 10" Active Subwoofer Project to mate up with the Fostex FE127E DIY Sealed Bipole Speaker Project. The plan from here forward is to host various DIY Audio Projects by myself and others. So, if you have a DIY Audio Project that you would like to share, please contact me via email.

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What's Playing
: Supertramp - Sister Moonshine

MAW-10 Subwoofer Project

Originally Posted: 30 October 2006

I am slowly working on getting my new site up and going, but in the meantime, I did manage to put the finishing touches on a DIY Subwoofer project. Below is the front view of a ported subwoofer project using a MAW-10 driver from www.mach5audio.com.

DIY Subwoofer Project

The enclosure is constructed from 3/4" MDF and active power is supplied by a partsexpress plate amplifier. On the underside of the enclosure is a speaker terminal so I can switch between passive and active power. The enclosure was finished with the same cream color paint used on the DIY Fostex FE127E Sealed Bipole Speaker Project.

MAW-10 DIY Subwoofer Project
The driver is still breaking in, but it already outperforms my JBL PB10. For more pictures and information, see the DIY MAW-10 10" Subwoofer Project page.

Update: 5 November 2007

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What's Playing: Monday Night Football

DIY Audio Winnipeg Meeting / Get Together

Originally Posted: 9 September 2006

The first diy Audio Winnipeg meeting was a success! I would like to thank all those who participated in the event. I had a real good time and it was very nice meeting some new faces and chatting about various diy Audio projects. Reaction to the meeting was positive and I think this is an event that we can likely pull off on an annual basis. Below are some photographs if the event.

DIY Winnipeg Audio Meeting
K-12 Tube Amplifier
K-12M Tube AmplifierKit

FE127E Sealed Bipole and 18FE127E Sealed Bipole and 18" SonoTube Subwoofer

LM3886 Gainclone and 12B4 Tube PreamplifierLM3886 Gainclone and 12B4 Tube Preamplifier
12B4 Tube Preamplifier and Little Wally Mono blocks12B4 Tube Preamplifier and Little Wally Mono blocks
CMoy Headphone Amplifiers and Digital Computer OutCMoy Headphone Amplifiers and Digital Computer Out

Also, I want to thank Mark from
www.mach5audio.com who generously paid for the room rental at the UofW.

CMoy Mint Tin Headphone Amplifier

Originally Posted: 21 June 2006
A while back I purchased a nice pair of cans ... Grado SR80 Headphones. When I bought them, I knew that they would drive me to build a DIY headphone amplifier. Well, here are the results ... A very simple CMoy mint tin headphone amplifier.

Grado SR80 Headphone and CMoy Amplifier
The CMoy is a very popular and easy to build headphone amplifier that can be fit into a mint tin. It can be used to drive demanding headphones, produce thunderous volumes and most importantly, it sounds excellent. The original article A Pocket Headphone Amplifier by Chu Moy discusses all the fine points of the amplifier, while How to Build the CMoy Pocket Amplifier provides excellent and easy to follow building instructions.
My version of the CMoy headphone amplifier uses two nine volt batteries, the OPA2132PA (Burr-Brown) operational amplifier (opamp) and I originally set the gain to 9 - which turned out to be far too high. I have since adjusted the gain down to about 3. Since I will be using this with a portable MP3 player, I elected not to include a potentiometer as the volume will be controlled through the MP3 player.

CMoy Headphone Amplifier in Altoids Mint Tin
The CMoy headphone amplifier sounds pretty darn good when you consider the simplicity and low cost. It provides excellent clarity, even at high volume. The headphone amplifier does not seem to add its own colorations to the sound and there is a lot of detail. The amplifier is very well behaved and there are no pops when powering up or hiss during operation. Overall, this is a very nice little performer and it considerably increases listening pleasure with a good set of headphones.
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06 November 2006

Fostex FE127E Sealed Bi-pole

Originally Posted: 13 June 2006
DIY Fostex FE127E Sealed Bipole Speaker Project
Another set of DIY full-range speakers! The small fellows in the picture are a pair of 23L sealed bi-poles speakers using the Fostex FE127E driver and built with MDF. Many thanks go out to Mark from mach5audio.com who did most of the woodworking. The wife pleaser in the middle is an experiment of his ... A 20" subwoofer in an open baffle! The test setup was a Luxman preamp, Behringer DCX and Luxman power amp. Cross over points between 80 and 120Hz were tested with 90-100Hz working well with the 20" open baffle sub. It was tough trying to place the speakers as we found the 20" sub was often in the way of the music, but we did manage to get it set up nicely. We were very pleased with the initial results and are expecting even better performance with a tube amp.

Overall, I am very pleased with the results from this very simple project. More information about this project and an enclosure plan is available on the DIY Fostex FE127E Sealed Bipole Speaker Project page.

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: Marc Almond & Softcell - Say Hello, Wave Goodbye

LM3886 Chip Amplifier (gainclone)

LM3886 ChipAmp (gainclone)Originally Posted: 3 May 2006

After several months of planning and acquiring parts, I finally got down to constructing a chip amp (gainclone). The amp uses the National Semiconductor LM3886 chip with printed circuit boards (PCB) purchased from chipamp.com. I finished the amp late last night, so I only have about 3 hours on it and I don’t think it is burnt in. So far it sounds pretty good. It sounds much better than it should given the simplicity and low cost of this amp. There is a lot of power available and the bottom end is very good. It sounds a little bright and tinny to me right now, but I will reserve judgment and make a comparison to my S-5 Electronics K-12M tube amplifier kit after several more hours. More information about this project is available at the LM3886 Chip Amp (gainclone) project page.

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DIY Audio Winnipeg Meeting

Originally Posted: 1 May 2006

The date for the 2006 DIY Audio Winnipeg meeting has been set for September 9, 2006. The meeting will be held from NOON till 5:00 PM at the University of Winnipeg downtown campus. All are welcome to attend this free event. If you have a DIY project that you would like to show off, please bring it down!

UPDATE - coverage of the 2006 DIY Audio Winnipeg Meeting / Get Together

Grado SR80 Headphones

Originally Posted: 17 April 2006
After reading a few articles at the HeadWize forums, I got the headphone bug and figured I needed a new pair. I spent a little time researching headphones on the net, and the Grado line of headphones, particularly the SR60 and SR80 were getting good reviews relative to their cost..

Grado SR80 Headphones

So I went headed off to the local Hi-Fi shop and gave a few "cans" a good listen. I did not want to break the bank, so I concentrated on the Grado line of headphones. I listened to the SR60, SR80, SR125 and SR225. As one would expect, they generally got better as you moved up the line. The SR60s seems to have the best bass of the bunch, but seemed a little dry in the midrange. To my ears, the differences between the SR80 and the SR125/SR225 were subtle, so I went with the SR80. If you prefer music with more of a thump, the SR60 are an excellent choice and also the lowest cost of the bunch.

A comparison of the measured frequency response (by headphone.com) is shown in the plot below.
Grado SR60 / SR80 / SR125 / SR225 Headphone Frequency Response Plot
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BD-Pipes with Radioshack 40-1197

Originally Posted: 22 January 2006

BD-Pipes with Radio Shack 40-1197Football sucked today! Jake Plummer should stick to taking field goal snaps.

On the bright side, I finished a BD-Pipes Project with the Radio Shack 40-1197 today! Almost two years of planning and finally some results. A special thank you goes out to Andrea and her dad at the Minnedosa speaker factory for all their fine carpentry work.

The drivers are 4" Radio Shack 40-1197 (FE103) full rangers, two of them per enclosure and thus no need for a baffle step compensation (BSC) circuit! The speakers are still being broken in, but thus far they sound pretty darn good. I am surprised how much bass these little four inch drivers produce. Being full range, the imaging is great. So far, I am pretty pleased with the sound. I'm looking forward to hearing how these sound when they are broken in.

For additional information about this DIY Speaker project, see the Radio Shack 40-1197 BD-Pipes Project page.

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