Author Topic: DIY 2A3 or 300b kit  (Read 21890 times)

seadogs

  • Guest
DIY 2A3 or 300b kit
« on: December 11, 2014, 10:46:31 AM »
Hi, all

I am looking to build my own 2A3 or 300b Mono block amps, and matching tube pre-amp and need advise.  It is my first venture into amp building.  Can, i buy a complete kit or is it better/ cheaper to buy it all individual. read something about the Moondog 2A3 Monoblock Amplifiers and  Laurel II 300B Monoblock Amplifiers     any advise will be greatly appreciated, thanks   

Offline Brap

  • Obsessively Audiophilic
  • ****
  • Posts: 283
Re: DIY 2A3 or 300b kit
« Reply #1 on: December 11, 2014, 11:31:33 AM »
You may want to check out Transcendent Audio. I built the SOB kit and am contemplating their Masterpiece Pre-amp. They have a great forum too.  The SOB OTL amp rocks big time with efficient speakers.
Fritz Carrera 7 Be
VTA ST-70
Parasound Halo P5
Oppo 105
Rega P3
Ortofon Quintet Bronze
Cambridge CXN streamer
Teac 3340S
Anticables 3.1
Masterbuilt reference/Kimber Cable IC

Offline BobM

  • Audio Neurotic
  • *****
  • Posts: 3318
Re: DIY 2A3 or 300b kit
« Reply #2 on: December 11, 2014, 11:32:24 AM »
The adventure of building something yourself is always a great one. You will likely learn a lot. Just be careful, make sure your solder joins are good, test along the way, power it up slowly with a varistor.

Basically, a decent kit will also have decent instructions. Read a few on-line articles on DIY tube amp building before you start to see what you are up against. Tube amps have high voltage, and can be dangerous. Can't emphasize that enough. But to me, DIY is a whole 'nother end to this hobby that many people don't explore, and it can be very rewarding.


Laugh and the world laughs with you. Cry and you'll have to blow your nose.

Offline shadowlight

  • Obsessively Audiophilic
  • ****
  • Posts: 990
Re: DIY 2A3 or 300b kit
« Reply #3 on: December 11, 2014, 01:35:35 PM »
Once I get comfortable in reading schematics and working with tubes.  I plan to build 6CB5A based amp based on Thomas Mayer.  Link to articles on where he lays out everything and does a pretty good job of explaining.

http://www.diyaudio.com/forums/tubes-valves/235980-schematic-learn.html#post3490993

Offline richidoo

  • Out Of My Speaker Cabinet
  • ******
  • Posts: 11144
Re: DIY 2A3 or 300b kit
« Reply #4 on: December 11, 2014, 04:35:18 PM »
Welcome to AudioNervosa seadogs!!

Since it is your first amp project, I would strongly recommend to buy a complete kit with all parts included, and which also provides good tech support. When you make a goof you will be very glad you picked a kit with good support.

Welborne Labs doesn't make the Moondog kit anymore. I don't see any kits for sale there, only assembly manuals. Do they still sell kits?

TubeLab offers proven designs as PCB only. http://tubelab.com/

Tubedepot imports tube amp kits: https://www.tubedepot.com/t/diy-central/kits-tube-amp/hifi-tube-amp-kits

Oddwatt: http://www.oddwattaudio.com/

Bottlehead: http://bottlehead.com/

Transcendent Sound: http://www.transcendentsound.com/

Vacuum Tube Audio: http://www.tubes4hifi.com/

Triode Electronics: http://www.triodeelectronics.com/hifikits.html


For preamp, most of the above offer preamps also, but one brand offers excellent preamp kits but no amps.  Glassware Audio: http://glass-ware.stores.yahoo.net/index.html

Look at their Aikido preamp kits. They are well loved among the DIy community, many MANY have been built successfully and they sound very good.

Offline sleepyguy24

  • Obsessively Audiophilic
  • ****
  • Posts: 904
Re: DIY 2A3 or 300b kit
« Reply #5 on: December 11, 2014, 05:18:54 PM »
I would give Bottlehead a try. I'm happy with their BeePre 300B preamp.

This is their amplifier kits.

http://bottlehead.com/product/paramount-v1-1-300b2a3-monoblocks-pair-kit/

Good luck and welcome.

seadogs

  • Guest
Re: DIY 2A3 or 300b kit
« Reply #6 on: December 12, 2014, 05:44:01 AM »
WoW   Thanks guys for the input, I will go thru all the links and take a look at them.  Just wondering how i know what is good/great parts or just crap.  Should i look at other well known amp manf  and see what parts they use, and adjust accordingly  thnaks for your help and will keep you posted :-)

Offline tmazz

  • Out Of My Speaker Cabinet
  • ******
  • Posts: 12088
  • Just basking in the glow of my tubes.....
Re: DIY 2A3 or 300b kit
« Reply #7 on: December 12, 2014, 07:49:21 AM »
Welcome aboard seadogs! Good luck on your adventure. The first amp I bought when I started to dbble in high end audio was a Hafler DH-220 that I built from a kit. It was a fun thing and I have been actually beeen thinging abouttrying my hand at building a tube amp in the near futre (although I would need more power than a 300B set am can provide. There are a few guys out there selling kit based on old Dynaco designs that looked like they could be fun to play with.)

BTW - what kind of speakers areyou going to drive with this the 300B amp?
Remember, it's all about the music........

• Nola Boxers
• Sunfire True SW Super Jr (2)
• McIntosh MC 275
• ARC SP-9
• VPI HW-19 Mk IV/SDS/SME IV/Soundsmith Carmen Mk II ES
• Pro-Ject Pre Box S2 DAC/Rasp Pi Roon Endpoint
• DigiBuss/TWL PC&USB/MIT Cables

Offline richidoo

  • Out Of My Speaker Cabinet
  • ******
  • Posts: 11144
Re: DIY 2A3 or 300b kit
« Reply #8 on: December 12, 2014, 09:44:26 AM »
WoW   Thanks guys for the input, I will go thru all the links and take a look at them.  Just wondering how i know what is good/great parts or just crap.  Should i look at other well known amp manf  and see what parts they use, and adjust accordingly  thnaks for your help and will keep you posted :-)

Tube amps use expensive parts, so a kit with good quality parts will not be the cheapest choice, but it will be better designed and will sound better. The output transformer is the most expensive part. Big size makes it better, which means more iron and copper and thus more shipping weight. Transformers tend to be shortchanged in kits and low cost tube amps. As a DIYer you kinda have to use your faith, research and instinct to fess out a project before you commit. Read about the kit, other builders' experiences, preferably there is a builders' support forum. Search diyaudio.com for threads pertaining to your kit. Google the kit and the seller for dirt. In the end it's a leap of faith to do a DIY. even if the kit is quality and builders are happy, and you build it perfectly, it may not gel with your speakers.

Tom's question about your speakers is the most important one of all. 2A3 makes 3W? 300B makes 8W. Your speakers should be high efficiency types, with 95+ sensitivity for the 300B and 100dB sensitivity for a 2A3 in order to play music loud enough to get you moving.   :dj:

Offline tmazz

  • Out Of My Speaker Cabinet
  • ******
  • Posts: 12088
  • Just basking in the glow of my tubes.....
Re: DIY 2A3 or 300b kit
« Reply #9 on: December 12, 2014, 12:09:36 PM »
And of course any time you are dealing with their flea size output wattages typical of SET amps noise becomes a huge factor. Given the hyper efficient speaker designs that you need to use a SET even the slightest amount of noise will become instantly audible, and annoying.Think about is, with my big Thiel 6.0s and the 200 watt Audio Research amp if I had 2 or 3 mW of noise it was not that big of a deal compared tot the wattage being used to drive the speaker. However: if that same 203 mW of noise is present in an amp they only puts out 2 or 3 watts total, it quickly becomes very significant in comparison to the signal. (Just do the math and figure out what the acoustic outputs of 104 db and 87 db efficient speakers are and you will see what I mean.)

So not only do you need a well designed amp but you must be very careful in terms of wire routing and soldering when you assemble it. It is not easy to get right. There is a reason why those flea wattage SETs cost as much as they do.

That said, this doesn't mean it can't be done, just that you really need to take your time and pay extra attention to detail when you do it.
Remember, it's all about the music........

• Nola Boxers
• Sunfire True SW Super Jr (2)
• McIntosh MC 275
• ARC SP-9
• VPI HW-19 Mk IV/SDS/SME IV/Soundsmith Carmen Mk II ES
• Pro-Ject Pre Box S2 DAC/Rasp Pi Roon Endpoint
• DigiBuss/TWL PC&USB/MIT Cables

Offline richidoo

  • Out Of My Speaker Cabinet
  • ******
  • Posts: 11144
Re: DIY 2A3 or 300b kit
« Reply #10 on: December 12, 2014, 12:23:17 PM »
Another great point Tom.

The kind of details Tom is talking about are the reason why a beginner should use a well designed kit for the first build. Hopefully a wise and experienced engineer thought through all those subtle points and then engineered them into the kit.

Offline hogg

  • Certifiable
  • ***
  • Posts: 210
Re: DIY 2A3 or 300b kit
« Reply #11 on: December 12, 2014, 07:39:12 PM »
Here's another 300B kit that permits different power tube rolling.

http://www.vkmusic.ca/elekitnew.htm


                                               Jim
Strong as an Ox and twice as smart

seadogs

  • Guest
Re: DIY 2A3 or 300b kit
« Reply #12 on: December 15, 2014, 07:10:35 AM »
Hi all

  I went thru all the amp kit website and some better than others and i came across this when i was looking at the 2A3 amps.
 http://www.finaleaudio.com/300b-set-mono-blocks-kit/ and have talked with the sale rep, and i am very impressed,  They are not pushy and he seems like he wants to  inform me, and make sure im getting the right match with my speakers and listening habbits over just selling me an amp/integrated.   Two thumbs up Finale/Triode Labs
 My speakers are Zu's  101 dB's   I will let everyone know if i go with the Mono's Kits or just buy the Mono's 2A3's   

Offline Response Audio

  • Industry Participant
  • *
  • Posts: 1003
  • Build your system for yourself, not the critics
    • Purity Audio Design
Re: DIY 2A3 or 300b kit
« Reply #13 on: December 15, 2014, 08:18:23 AM »
You may also want to look at Audio Note Kits. They have a few really good 2A3/300B kits available as well as preamps.

I have built dozens of these for customers and they are very nice for the money. You can always upgrade components later if (actually 'when') the urge gets ahold of you.

The manuals are very friendly to even the first time builder.

Just throwing another option on the table for you.
Design Engineer
Purity Audio Design www.PurityAudioDesign.com
Purity Foundation Streaming Pre, Foundation DAC, Purity Foundation Hybrid GaN 200, Pure Audio Project Trio 15 Classic, Sony SACD Player, Nakamichi tape deck,

Offline shadowlight

  • Obsessively Audiophilic
  • ****
  • Posts: 990
Re: DIY 2A3 or 300b kit
« Reply #14 on: December 15, 2014, 10:11:12 AM »
Hi all

  I went thru all the amp kit website and some better than others and i came across this when i was looking at the 2A3 amps.
 http://www.finaleaudio.com/300b-set-mono-blocks-kit/ and have talked with the sale rep, and i am very impressed,  They are not pushy and he seems like he wants to  inform me, and make sure im getting the right match with my speakers and listening habbits over just selling me an amp/integrated.   Two thumbs up Finale/Triode Labs
 My speakers are Zu's  101 dB's   I will let everyone know if i go with the Mono's Kits or just buy the Mono's 2A3's   

Frank @ Triode Labs / Finale is easy to deal with.  He answered endless questions when I purchase the 2a3 amp.