Reference tube amp kit, <20 watts for under $1,000?

[freax]

He also has an interesting DIY speaker project using full-range Tang Band 8" drivers. I built a pair for <$600 and they sound excellent for that $$$. 95dB sensitivity is very loud with 3W. They will work nicely with 1W and scream with 15.

Transcendent Sound DIY Specialist in Vacuum Tube OTL Amplifiers

I would be interested in a DIY speaker if it involved a single large 12" driver on the bottom in addition to a full range driver on the top /or/ it was a single 8" full range driver with an easy to build speaker design that went all the way to the floor and met up at my ears at a Height of 35 inches from the floor on average.

With a room of these dimensions: 10ft x 10.5ft and 8 ft high.

I want something REALLY big, something with a very large driver for bass but also very very efficient, something that is floor standing.

I'm still looking over my options on this matter

 

[tubemax]

Hi,

Maybe Audio Nirvana 15 inch full-range driver in 5,6 cu inch BR box...
One driver, no crossover, ±97db sensitivity, big box, big sound... it seems nobody is complaining about this driver...

 

[skippyboy]

I just finished this kit,
http://www.diyaudio.com/forums/vendors-bazaar/180897-kt88-se-basic-master-kit.html
Sounds great, i supplied my own chassis and the documentation was superb
Rob

 

[freax]

That sounds PERFECT!!!

I'll look into it with intense interest.

I even have a couple of NOS GE 6L6 tubes too, using them shouldnt be impossible

 

[freax]

I've decided and I've figured that the OTL design is simply outside of my budget, not because I cant afford to buy it but because I cant afford to RUN it with the cost of electricity being so high.

I want to be able to listen to my amps as often as possible, not just within the hours of 10pm - 7am

The old sony does have one thing going for it, when paired with my apple tv (1watt) and my ipad 3 (battery power) and the sony amp (0 watts when off at the front, no really, I was surprised too, and 13 watts when powered up) that combination simply cannot be beat during the daytime for low energy consumption.

Airplay enables me to send audio from my ipad from either soundcloud or the shoutcast app, while I am doing other things on my ipad 3, like write this post, to my apple tv and consequently to my amplifier via the optical output.

I dont even need to have a monitor hooked up to the apple tv because it always responds to a request from the ipad 3 to stream audio to it over airplay.

I think its an apsolute cruel joke on the part of acer to have a monitor that draws 7 watts when its off.... thankfully a digital timer shuts everything down when I dont need it.

 

[Alan Cohen]

I want to be able to listen to my amps as often as possible, not just within the hours of 10pm - 7am

I hear that. Mine is on from the minute I walk in the door until I leave or go to sleep.

I had no idea electricity was so expensive down there.

I have a vintage pop-up camper circa 1969 that I recently installed a deep cycle battery and inverter into so me and my boys can have a little juice when we're in the woods. From that experience they have learned not to take electricity for granted. If they leave a 7W light on for an hour, that's 2 hours less computer time they will have.

We added some solar panels this year which helps, but we also added a 115V fridge and TV. My oldest snottily asked me. "so when is it not camping anymore, Dad?" I quipped back, "the day you first brought your GameBoy along, we were no longer camping". "Any more questions"?

So anyway, now I understand your hesitation with OTLs. But as a tease, my 15Wer is done and burning in...

 

[freax]

I must say the view is breathtaking!

Thank you for sharing with me! It put a smile on my face

 

[costis_n]

I would be interested in a DIY speaker if it involved a single large 12" driver on the bottom in addition to a full range driver on the top /or/ it was a single 8" full range driver with an easy to build speaker design that went all the way to the floor and met up at my ears at a Height of 35 inches from the floor on average.

With a room of these dimensions: 10ft x 10.5ft and 8 ft high.

I want something REALLY big, something with a very large driver for bass but also very very efficient, something that is floor standing.

I'm still looking over my options on this matter

For big, easy to build and efficient, you could do a lot worse than this, inspired by one famous thread in some other forum. Drivers are in ear level.

 

[freax]

Wow are those baffle curtains!? amazing!

I question the use and placement of a dryer drum though in the room....

Thank you for sharing! and please PM me with any further details on them.

 

[tubemax]

<I've decided and I've figured that the OTL design is simply outside of my budget, not because I cant afford to buy it but because I cant afford to RUN it with the cost of electricity being so high.

I want to be able to listen to my amps as often as possible, not just within the hours of 10pm - 7am>

Hi Freax,

Maybe is time to re-think about some class D chip amps if electricity bill is the issue - as far I know there are no tube amps with power consumption less than at least 100 WATT's of total power waste for a amp.
300B SET class A amp is even less efficient for a given watt of power than PP tube amp... but then we are not talking about reference amp anymore?
I have sold my 300B SET after hearing good OTL - there is just no comparison... two pictures of my past 300B & 6AS7 OTL.

Max

 

[freax]

The other criteria is that it needs to be in kit form, I would build it myself but sourcing the components is expensive to say the least and importing and making the chassis puts me up up in a tuffe about cost aswell.

Then I've got issues with inexperience surrounding how to lay everything out, where to put solder terminal strips, plan it all out in my head, etc.

With this KT88 amp kit, I can have a nice everyday amplifier /and/ at the same time learn how to lay things out, and gain experience in doing so, its the hands on experience that I need.

Maybe next year I will buy an OTL amp I could certianly just keep the older KT88 amp for a spare or use it in some other way.

So this year: KT88 SE.
Next year: Set of speakers.
Late Next year OTL EL509 or 300B amp.

Thanks for the pics!

 

[Alan Cohen]

I have sold my 300B SET after hearing good OTL - there is just no comparison... two pictures of my past 300B & 6AS7 OTL.

OT, but how about some OTL 300B monoblocks!! The same guy that designed my 15W OTL has also designed a killer 1W 300B OTL. I have the schematic and parts list from his book, but kits are forthcoming and I think I'll wait. Not exactly economical, but the nuanced detail and imaging is purported to be second to none.

My long range plan is to bi-amp my Altec drivers, running the 300B monoblocks into the horns and the 15W OTL into the 15" drivers.

This rig should be a recording engineers best and worst friend.

This is a pic of the amp done by someone else in a wood chassis:

 

[Alan Cohen]

Maybe next year I will buy an OTL amp I could certianly just keep the older KT88 amp for a spare or use it in some other way.

So this year: KT88 SE.
Next year: Set of speakers.
Late Next year OTL EL509 or 300B amp.

Thanks for the pics!

My current amp is a KT88 based cathode follower. It is 3W/ch of audio heaven and maybe the clearest amp short of an OTL.

Sadly, it is not available in kit form any longer. Bruce says it was his worse selling kit ever, but since it's been discontinued it has developed a cult following...me included. I sourced out the parts from a few suppliers and it ended up costing around $575 all up.

Here's a link to Bruce's page...

Transcendent Sound Cathode Follower Tube Amp

And my build thread. If you read through it you will see I am not the most experienced builder. This was my second project and a great learning experience.

CFA Build... - Transcendent Sound Message Board

After the 15W is running I plan on moving the KT88 amp over to my TV.

 

[freax]

I'm torn between the 6L6-GC Elekit TU-879S and the KT88 SE kit.

Can the frequency response of the Elekit be believed?
Elekit: http://www.vkmusic.ca/TU-879S.htm
Frequency characteristic (-3dB): 20Hz - 43,000Hz

KT88 kit: http://www.diyaudio.com/forums/vendors-bazaar/180897-kt88-se-basic-master-kit-6.html#post2705221
Frequency Response: 30Hz ~ 20,000Hz -1dB, 20Hz ~ 22,000Hz -3dB

I think the KT88 kit would have a far more greater response, mainly because the Elekit has smaller output transformers.

I've got half a day to decide, 12 hours from the time of this posting before its completely final.

I'm currently looking over the smaller OTL amps on Transcendent sound atm.

 

[freax]

The mini beast is winning my heart, but there must be something wrong with that power consumption figure? 290 watts? for 6x el509 tubes and 2x 6H30pi

all of that power is dissipated on the B+ ? wow

I'll shoot off an email to him. < nevermind, it says so in the description.

 

[freax]

mmm nice, very nice: http://www.diyaudio.com/forums/elekit/158462-elekit-tu-879s-6l6gc-4.html#post2576724

 

[Alan Cohen]

The mini beast is winning my heart, but there must be something wrong with that power consumption figure? 290 watts? for 6x el509 tubes and 2x 6H30pi

The SOB has the lowest power consumption of any OTL amp due to it's simplified circuitry and push/pull configuration. The MB, being single-ended, puts off more heat.

The 15W of the SOB makes speaker selection less critical as well. It will drive almost anything.

 

[freax]

It doesn't matter now anyway, I just asked Scott17 for an invoice and I'm staying up tonight to pay for it so I can get it (KT88 SE Master Kit) as soon as possible.

SOB OTL will have to wait until late next year

Thanks for your persistence in this matter, but every watt that I can shave counts, if I can justify spending $1,000 on a 160 watt OTL amp that only gets run only during off peak hours then I will bite on the SOB OTL.

 

[Assiehoussou]

Yeah, I'll think about the OTL amp, thanks for your help guys.

Alright, I'll go with the OTL amp.

Removing those output transformers from the signal path is what convinced me that its a good idea regardless, that and the fact that I've currently got speakers that will sing just fine at 15 watts (Sony SS-212's), and that it consumes the same amount as an ST-70...

And that 10 watts tube power is enough for me, but 15 watts is even slightly better.

And I can always roll a couple of chip amps for the 12inch or 15 inch down throwing drivers.

Hello Freax

Like you I've got a pair of Sony SS 212 (40W 8 ohms) dating from my student years. I'm desperetaly trying to find an equivalent for one of the medium speakers which is out of service. Do you have an idea ?
Thanks in advance