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    Building, troubleshooting and testing of these amplifiers should only be
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    the safety precautions around high voltages.

Need Tube kits of above 75W Single Ended Class A amp

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75W power output in SE means you will have to dissipate around 180W if you use pentodes, or something like 300W if you use triodes or triode strapped pentodes (my math is only very rough but I think it's in the right ballpark)

This is VERY HOT.

The biggest triodes people typically use can dissipate around 100W (there are some bigger ones but practicality goes down very rapidly), which means you get around 20W power output in SE. A power supply in the kilovolt range is required.

This is to give you an idea of the (in)efficiency of these things.

The practical limit for a beginner is to aim for about 10W power output, which is attainable with tubes like the KT88. The difference in loudness between 10W and 75W is probably not as great as you'd expect, so you will probably not be disappointed.

I recommend going here:

http://www.tubelab.com/SimpleSE.htm
 
pokerking said:
Ok i can reduce wattage. I want to start with SE amplifier kit. Any more proven kit in SE mode?.

I can use low wattage for headphone listening also.

Building A 75W SE amp is a major and rather expensive undertaking. You would not do that if the goal were to save money. The major cost will be the large transformers.

Best that you start with a smaller project. Look at the Tublab Simple SE. It's built on a PCB. If build as a headphone amp it can be in-expensive. Many people here have experience with this amp.

http://www.tubelab.com/SimpleSE_board.htm

The only problem with this amp is that it is built on a PCB. Nothing wrong with PCBs but if the goal is to learn how to hand build amps by hand using point to point or turret boards then this does not help that goal.
 
Re: 60w kit

athos56 said:
I've almost pulled the trigger on this kit a few times. Check epay listing number (290326288158) no affiliation...

The above looks to be a push pull design. The OP was looking for a 75 WPC single ended design.

That said. Thanks for pointing this out. I have a pair of 1970's vintage Infinity speakers that need 100W to sound their best. They are very inefficient. "Some day" I will have an amp that can drive them well. I'm using a vintage Luxman SS amp now and it's only "ok".
 
pokerking said:
Watts do not matter. I need SE mainly...

While not strictly a kit, there is more than enough documentation available for you to source all the parts with thinking about it too hard. You'll need to fabricate a chassis, or buy a professionally drilled one from an outfit like Front Panel Express. This amplifier is a single ended design using the 6B4G as the output tube. It is roughly comparable to the 2A3.

http://www.diytube.com/phpBB2/viewtopic.php?t=3382

I built one recently, and I'm pretty pleased with it.

 
pokerking said:
So cost is going to be big factor as wattage goes up. I need full kit with enclosure except tubes.

May be just buy chinese Tube amplifier? for 600 bucks?.

The way to decide to build or buy is if you like building. If you want to learn about amps and how to cut metal parts and solder then build one. If you just want an amp and see building one as a chore then buy one already made.

If you want to learn it's best not to build you "dream amp" as the first project. Build a small headphone amp or something like that. These can be very simple and low cost After you build that first project you will know 100 times more than you do now and be able to make a better decision about what amp to build next.

When adding up the cost, be sure and add in the price of tools and test equipment. You will need to "test as you build"
 
i only see 8w or 16 W....anything higher like 35w - 50w SIngle ended?.

Because whole purpose of building this monster is power the Electro static speakers once i have enough money.

DO not want to waste too much time on headphone amp. i won't be listening in headphone anyway.
 
pokerking said:
i only see 8w or 16 W....anything higher like 35w - 50w SIngle ended?

You'll need to move to something like a 211 or an 845 tube to get closer to that kind of power, and even then they'll still come up short of your desired wattage (mid 20s). These transmitter tubes require very high voltages (>1kV). This is not a project for a beginner. Expect the necessary output transformers to be fantastically expensive. The 845 has a relatively high plate resistance, which means you'll need mountains of inductance in your OT. Think fifteen pounds each.

If single ended and high power are requirements, your other option is to move to parallel output tubes. You'll still need the fantastically expensive output transformers. The drive requirements become more complicated. If you're going to put more than one output tube on a channel, why not go push/pull? It isn't inherently evil.
 
my last DIY project was a pair of (roughly) '20W' single ended monoblocks. I used the EL156 output tube in ultralinear driven by a pentode. Total cost, even with pedestrian Hammond parts was roughly $1100. Figure doubling the cost for the power transformer and output transformer needs if you decided to increase the power by paralleling output tubes.

Really with that kind of investment for driving low efficiency 'stats I would go for big push pull power be it solid-state or tube.
 
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