[M797]

Greetings from New England, USA.
I'm new here and hope to learn some more about speaker modifications and room acoustic treatments.
I love DIY audio. I've built many amplifiers and a great pair of speakers.
It's certainly the best way forward for people who insist on excellent sound but refuse to pay up for expensive brands.
DIY gives us choices for the design topology and the parts selection. With DIY, we can create things that perform far better than name brand products for less cost. I can repair equipment and I like to improve equipment with modifications. I studied electronics, music and the technology of recording in school.
I worked in recording studios as an engineer in the '80s and and later focused on music production and performance. 
I have lots of DIY audio/electronics projects in the works at different stages to keep me busy but I really enjoy the Listening to the Music part of the experience.
 

[FullRangeMan]

It's certainly the best way forward for people who insist on excellent sound but refuse to pay up for expensive brands.
DIY gives us choices for the design topology and the parts selection. With DIY, we can create things that perform far better than name brand products for less cost.
Welcome to AC, I second what you said above on DIY
I have found this interesting simple amp project>
https://www.audiocircle.com/index.php?topic=179626.0

[mresseguie]

Welcome to AC.

I wish I had half the DIY knowledge and know how as you profess to have. I know. I'll never learn if I don't get my hands dirty. 

Michael

[Phil A]

Welcome!

[planet10]

\I love DIY audio. I've built many amplifiers and a great pair of speakers.

Welcome to the forum. Examples of your builds?

dave

[M797]

Thanks for all of the welcomes.
FullRangeMan, I thought the MoFo amp that you link was interesting too. I bought the bare boards and already had a pair of the big inductors.
Finding a decent looking chassis with the huge heatsinks looks like a big problem. I build the Whammy HP amp and run it at 24 volt rails so it will drive that for sure. This one is on hold.

Planet10, some examples of my builds are:

A pair of Hammer Dynamics Super 12 speakers in Baltic Birch with lots of rosewood edge trim and internal bracing.
J.C. morrison's DC coupled two stage 2A3 amp from Sound Practices Magazine. It's now a guitar amp.
A pair of monoblocks of J.C. Morrison's Screen driven beam power tetrode parallel single ended amps which are also DC coupled.
A pair of 45 step ladder attenuators with Shalco switches and mostly Holco resistors in a box with a six input selector.
An Audio Note DAC kit 1 that has been extensively modified. I was able to get a pair of the silver wound interstage transformers for cheap and added them. I added regulated filament voltage, 1K series resistors on the data and clock lines, replaced HV power supply series resistors with chokes, added snubbers to the power supply transformers. I really like this DAC!
I've built a pair of Glass Audio Aikido Cathode Follower buffers.
An regular Aikido preamp and an all in one 5687 Aikido preamp. Both of which need chassis, coupling caps and power supplies.
A Glass Audio Janus high voltage regulator.
Pete Millets Korg NuTube preamp.
Pete Millets test and measurement interface for sound card.
Lots of Jung Didden Super Regulators.
A pair of Sound Skulptor MP73 microphone preamplifiers based on the Neve 1073 console design.
A Sound Skulptor MP32 transformerless input wide bandwidth mic preamp using two discrete op amps and a Lundahl output transformer.
An API console style microphone preamp with transformer inputs and outputs.
A WHAMMY headphone amp/preamp with discrete opamps and 24 Volt rails.
I'll end this list with a picture of my unfinished Pass F6 Amplifier because it's kind of funny how it became a real layout puzzle. I went dual mono with two power transformers in the chassis and a soft start and speaker protection board. Now I have to fit in 16 Mundorf electrolytics and I'm not looking forward to it. It will all fit if I stack the capacitors one over the top of the other with the pins meeting together. I want to add the silver plated copper strap between for ground bus. One unique thing I did was replace the single speaker relay on the speaker protection board with a pair of Amplimo speaker relays. They have two sets of contacts. One to draw and arc on opening and another silver set for the signal path. They sit on Sorbothane bushings to keep the vibrations away.

Thanks for the opportunity to brag about my builds!

[FullRangeMan]

Finding a decent looking chassis with the huge heatsinks
I though I could use only that RF Parts heat sink with no chassis at all since the parts count are small.

[M797]

I didn't see the picture that I thought I had attache so will try again.

[M797]

Welcome to AC.

I wish I had half the DIY knowledge and know how as you profess to have. I know. I'll never learn if I don't get my hands dirty. 

Michael

Michael,
Show us your hands!

[planet10]

Hammer Dynamics Super 12 speakers in Baltic Birch...

J.C. morrison's DC coupled two stage 2A3 amp...monoblocks of J.C. Morrison's Screen driven beam power tetrode parallel single ended amps...45 step ladder attenuators … Audio Note DAC kit….

We struggled with that speaker. Parts ended up being sold off, the cabinets burned nicely.

A lot of nice stuff you have built. F6 picture is broken. I have a few of Nelson’s amps.

dave

[M797]

We struggled with that speaker. Parts ended up being sold off, the cabinets burned nicely.

A lot of nice stuff you have built. F6 picture is broken. I have a few of Nelson’s amps.

dave

Thanks Dave. I reposted the F6 picture but at the moment I see that it's awaiting approval from a moderator.
I really like the concept of the Hammer Dynamics Super 12 in that it is a full range speaker that crosses over way out at 10kHz. That means there is none of the crazy crossover problems in the important areas of the audio that we focus on in normal listening. I went all out on the build and was very pleased with the result although it did not have the bass extension that I'd hoped for. But it was so engaging to listen to that I never got around to getting subwoofers. Right now, I've got one of them open and the woofer out because it has a nasty tear in the paper. I never mounted the crossovers inside the box. I used a pair of copper foil DIY cables (Allen Wright's DIY cable book) and snuck them out of the rear panel edge and put the crossovers in boxes on the floor. Now the copper foil ribbon cables have taken on small air leaks and all turned dark from oxidation. I'm going to put a couple of pairs of deep binding posts on each and re-wire the internals. I'm still going with the outboard crossovers but with a better looking box. I'll attempt another upload of pictures of these speakers during the build stage. Lots of hard wood bracing and asphalt sheet inside. Blue tack putty on the woofer baskets. Deflex panels on the magnets and rear panel. Blue tack putty rounding some areas inside the box out too. What was your experience and background with the Super 12?

[M797]

Another picture of my Super 12 Build.

[M797]

Finding a decent looking chassis with the huge heatsinks
I though I could use only that RF Parts heat sink with no chassis at all since the parts count are small.

Well it looks real nice but the devices are running super hot in that design. That looks like the kind of heat sink made to dissipate a bunch of devices in a row at lower current. I'm only looking at what other people started out with for heat dissipation on their Mofo and not running the thermal resistance numbers.
Let me know how it works for you. I'm leaning toward the big ugly heat sinks and searched around some awhile back but wasn't getting any good results.
Let me know how it works out.

[planet10]

In the Hammer DYnamics the high XO only works because the tweeter is (sort of) co-axial which dramatically lowers the combing issues with a tweeter crossed really high. But in this case the big main driver does not really reach the tweeter.

If you flip things over and put the XO really low most of the issues with an XO can be eliminated.

but, key to things, is that you enjoy them.

dave

[M797]

Dave,
That's interesting. If you could show me some of the crossover changes that would help. With the dual binding posts I will be able to bi amp and use a DSP crossover if I want to. I've kind of been avoiding the DSP crossover idea because I dread the AD/DA conversions. Although the concept of DSP crossover is a perfect solution for many shortcomings.  I'm so in love with my Audio Note DAC that It's hard to imagine not having it in my system. Does anyone know of a DSP crossover or DIY version that has digital inputs and outputs? I went through a period where I considered DSP crossover and didn't find anything practical that would work for me (meaning I'd be stuck with their converters).

Some years back the late Charlie Kittleson hosted an audio show in New Jersey when I lived there at the shore. Of all the listening rooms that they had only two stood out as amazing. One was Audio Note and the other was a brand that I have forgotten. There were a few that were good and a lot more that weren't good at all. I came away from this show with a huge grin and a proud feeling because I preferred my DIY system over all but those two rooms in the show.