Jump to content

Why I DIY


Cantilope

Recommended Posts

Making some changes to my amplification today and I wanted to share with you my process. For many years I purchased amplifiers infrequently over the years as they were rather expensive. Mainly I stuck to used gear as many of us do. One of these used amplifiers the First Watt M2 was so good that I decided I needed multiples of them to run bi-amp on my Jubilees. Talk about getting expensive, multiples! On this site I met William who convinced me that I should learn to build my own. So what you are seeing here is about 2 years of his tutelage and a skill I am rather new at. I watched a few military soldering training videos I found on Youtube and bought a an iron. Hopefully you can see the value in the education and ability to simply change a board and get a totally new personality. Maybe you'll like maybe not, but much like a car model as a kid it was a blast to build and test. So here we go...

 

In this photo you can see my case. This is a universal case, with a universal Power Supply form DIY Audio, and a transformer sized for many First Watt applications. I have just got done removing the F7 boards I have been running as of late. Took about 5 minutes.

 

IMG_6780.thumb.jpg.f3dda06a7879fb48cac4b75073180c93.jpg

 

In this Photo you can see my options. I have a F1, F3, Aleph J, M2, BA-2, or the F7s I just removed. I'll be choosing the BA-2 as I have not heard those yet, but hopefully you can see how really easy it is to change these boards and why for a just a few hundred bucks you can really explore what you like in SS amplification. Almost as easy as tube rolling...

 

IMG_6781.thumb.jpg.a4345fca85c4aac5ef2d528e019faa45.jpg

I'll post up one more once I have her up and running with the BA-2 boards (red ones) installed.

 

Joe

  • Like 1
Link to comment
Share on other sites

So here we are, a BA-2. Looks like it took me about 4 hours to change that out. (sorry the ba-2 boards have no flashy LEDs...) I need to bias these up as it is the first time. I'll throw it on the LaScalas tomorrow and give it a listen.  I need a reeb.

IMG_6782.thumb.jpg.2f4c0b453766e2b6000327b183b0df68.jpg

  • Like 1
Link to comment
Share on other sites

Since I don't do A/B testing, I really try and not give my opinions. I feel they are tainted...

 

However, with that, I'd say the M2 has more tube characteristics, where as the BA-3 is just a really clean SS amp. The M2 I believe is self-biasing where as the BA-3 is not. I was able to dial the bias a bit higher because I use a large case and large heatsinks on the BA-3 (twice the voltage as the amount in the build guide). The BA-3 also has a POT that allows you to dial in the amount of distortion with a turn. I have not messed with this feature yet. There is a video on Youtube by 6L6 that shows the results of this pot, and that you can introduce as much disortion as you like. Basically going from a sterile clean amp to something that has just a bit of the right kind of distortion. This is a very cool feature.

 

The M2 is much simpler build and set up and is a great "beginner"amp, but I suspect that the adjustability of the BA-3 makes it so I can tailor the sound to my needs, and that over time might give it the edge. The M2 is not as quiet as the BA-3 when there is no signal.

 

As far as the F7 that I removed, not one of my favorites, probably won't be used again, not as good as some of the others I have.

 

I hope this helps... 

  • Like 1
Link to comment
Share on other sites

I agree 1000%. I could not afford the amplifier technology I wanted. I've never done a solid state amplifier though. I've found I suck at circuit board work lol so I do mostly point to point. Your work looks great. I'm wrapping up a Brook 12A clones and a 112A preamp.

 

 

 

Link to comment
Share on other sites

  • 2 weeks later...

I wouldn't mind building one of these but with not having scopes and the ability  to test things, makes it something I shy away from anymore.  I can build cabinets and veneer them, I can build lots of different furniture, I can fiberglass kick panels for cars and wrap them in vinyl, I used to build motorized amp racks, and on and on....but building this kind of stuff is beyond me since I can't test them.  But I love reading about them.  I guess I need to stick to woodworking.  haha

Link to comment
Share on other sites

Well, I did build my Tubes4HiFi VTA ST-70 that came off with minimal hitches.  Those kits definitely made it easy to do with everything being laid out like it was.  It will be late in the year at earliest before I would have the chance to start on something...if not later.  We've bought land and are about to put our house on the market to sell then build a new one.  So, projects like this will be on the back burner for awhile.  I'll just follow everyone's builds for now.

Link to comment
Share on other sites

  • 5 months later...

Just want to let folks here know that this thread has inspired to build a Pass DIY F5 Turbo (V2) amp using PCBs and a 5U chassis from the diyAudio.com store. The 50 watts @ 8 ohms rating is really more for my KEF LS50 speakers than for my Klipsch Forte II’s, but I am sure that it will sound great with the Klipsch speakers too. Hopefully, when I finally move into a larger home and get my stuff out of storage, I can compare the F5 Turbo to my Texas Instruments TPA3255EVM Class D amp and McIntosh MC240 tune amp. 

 

I am preparing a BOM for parts and I will have to wait for the availability of the JFETs from Linear Systems. 

Link to comment
Share on other sites

Guest wdecho
10 hours ago, rhing said:

I am preparing a BOM for parts and I will have to wait for the availability of the JFETs from Linear Systems. 

You may be waiting a long time if they ever make them again. Right now the verdict is still out where they will be produced again. This is a reliable source on Ebay that Nelson has verified as a reliable source. 

https://www.ebay.com/itm/Toshiba-2SJ74-2SK170-LAB-MATCHED-QUAD-to-0-03mA-AND-4mV-7ma-range/253603371917?hash=item3b0bf05b8d:g:aJwAAOSw7I5TvEmk  or a little bit higher ma. rating. Either one will work fine. 

 

https://www.ebay.com/itm/Toshiba-2SJ74-2SK170-LAB-MATCHED-QUAD-to-0-03mA-AND-4mV-10ma-range/253517005056?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l26

 

Class A is still class, the purist form of amplification. Having built most of the Firstwatt clones I can say that the F5 is a very unforgiving amplifier. When the rest of your system is dialed in right it can sound fantastic, if not it will show every fault in the rest of the system. I have the F5 right now where I took out the speaker safety circuit using even less parts for a more purer sound. Good luck with your build. 

Link to comment
Share on other sites

Hi wdecho,

 

Thanks for pointing out the Toshiba JFET seller on eBay. I will purchase a set tomorrow. I am confident the F5 Turbo V2 will sound very good in my system. I will take my time in acquiring all the parts and build the amp as the weather turns cold. Then I can use the amp as a space heater too. 

Link to comment
Share on other sites

Guest wdecho
9 hours ago, rhing said:

Hi wdecho,

 

Thanks for pointing out the Toshiba JFET seller on eBay. I will purchase a set tomorrow. I am confident the F5 Turbo V2 will sound very good in my system. I will take my time in acquiring all the parts and build the amp as the weather turns cold. Then I can use the amp as a space heater too. 

It will definitely be a small space heater. It is the case anytime you go over 25 watts in class A. Sacrifice to pay for superior sound if you use other speakers beside Klipsch. With Klipsch speakers 10 watts of class A will be sufficient. 

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...