KT88 SE Basic or Master Kit

[scott17]

FEATURES & SPECIFICATIONS:

Single-ended class A operation
Multiple output tube selection – KT88, 6550, EL34 (KT88 included with Master kit)
6N1P-EV preamplifier tube (included with Master kit)
5U4-GB rectifier tube (included with Master kit)
Switchable operation mode for output tubes:
Triode mode: 5+ watt output per channel (with KT88)
Ultralinear mode: 10+ watt output per channel (with KT88)
Conservative tube biasing allows for extended tube life without comprising sound quality.
No semiconductor devices are used in the construction of this amplifier.

The Basic Kit includes:

1 - Assembly/Layout Manual on CD with full-color photos

Resistors
2 - 220K 1/4W Metal Film 1%
2 - 100R 1W Metal Film 1%
4 - 1K 1/2W Metal Film 1%
2 - 1.5K 1W Metal Film 1%
2 - 47K 3W Metal Film 1%
1 - 2 - 560R 10W Wirewound 1%
1 - 10R 5W Wirewound 5%
2 - 1M 1/4W Metal Film 1%

Capacitors
1 - 30uF MP Oil
2 - 50uF MP Oil
2 - Erse or Solen 10uF 630V
2 - Erse 0.22uF 630V
2 - Elna Silmic II 100uF 25V
2 - Elna Silmic II 220uF 100V
1 - 0.1uF 400V MP Orange

Connectors, Switches, Etc.
1 - IEC Power Entry EMI/Fuse
1 - IEC Power Cord for 120V USA kit only
1 - Front Panel Power Switch
2 - Neutrik RCA Jack one red, one white
2 - Dual Binding Post
1 - DPDT Toggle Switch
1 - 9-Pin Socket
3 - 8-Pin Socket
2 - 2” Capacitor Clamp
1 - 1.5” Capacitor Clamp
2 - Turret Board
1 - Aluminum Knob
1 - 100K Alps Volume Control
1 - 2A or 2.5A Slow Blow Fuse - dependent on AC operating voltage
2 - Hammond 155H 5H Choke

Hardware
16 - 4-40 Locknut
32 - 4-40 x 1/4” Screw
8 - 6-32 Locknut
8 - 6-32 x 3/8” Screw
3 - 6-32 Lockwasher
16 - 8-32 Lockwasher w/transformers only
8 - 4-40 x 3/4” Standoff
1 - #4 Ground Lug
1 - #6 Ground Lug
Crimp Terminal RED .187” 2 w/(120V kit) 4 w/(240V kit)
2 - Crimp Terminal RED .250” 2
Crimp Terminal BLU .187” 2 w/(120V kit) 0 w/(240V kit)
Crimp Splice 0 w/(120V kit) 1 w/(240V kit)
4 - Adhesive Tie Wrap Mount
12 - Tie Wrap
2 - Velcro Strip
1/8” Heatshrink Tubing - 18 inches
1 - 1.5mm Hex Key Wrench

All required wire.

Additional components included with the Master kit:
1 – Pre-punched Aluminum Chassis with Walnut Side Panels
1 – Aluminum bottom plate w/(4) #6 x 1/2” sheet metal screw

1 – PT750 Power Transformer w/mounting bolts & insulators
120/240V primary, 50/60Hz
750V, 200mA, center-tapped secondary
6.3V, 5A, center-tapped secondary
5V, 3.5A, center-tapped secondary

1 – Filter Choke w/mounting bolts & insulators
10 Henry, 200mA, rated at 500V

2 – Output Transformer w/mounting bolts & insulators
5000 ohm primary with 6 ohm secondary load
20-20,000Hz flat frequency response across band
120mA, 500V rated primary, 25 watt output

3 – 4.5” X 3.75” Powder-coated transformer end bell
1 – 3.75” x 3.125” Powder-coated transformer end bell

2 – Electro-Harmonix KT88EH Power Vacuum Tube
1 – Electro-Harmonix 5U4GB Rectifier Vacuum Tube
1 – Russian NOS 6N1P-EV Driver Vacuum Tube

Basic Kit $299.00 USD + shipping
Master Kit $849.00 USD + shipping

The Basic Kit is shipped in a USPS Large Flat Rate Box @ approx. 7 lbs.
The Master Kit is shipped via USPS in (3) boxes, 1 @ 11 lbs, and 2 @ 20 lbs. each.

 

[scott17]

KT88 SE Basic or Master Kit Photos

I currently have 10 Basic Kits available for sale.

The transformers and chassis will be available in 2 - 4 weeks at which time I will have 25 full Master Kits available for sale.

The photos of the completed amp are attached.

 

[scott17]

Chassis Depth

An important fact about the Basic Kit.

If you are providing your own chassis, make sure that it is at least 17"W X 10"D X 3"H.

If you would like to order, send a PM with your PayPal email and your shipping address. I will send a PayPal invoice.

Thanks,

Scott

 

[scott17]

One other important fact that I did not intend to be remiss in reporting:

If you're providing your own transformers, please pay attention to the transformer specifications as shown on the Master Kit transformer list.

Scott

 

[scott17]

If you are providing your own chassis, the hardware included in the Basic Kit will work with chassis top plate thickness of up to 0.125".

 

[Dave R]

I picked up my kit at the post office this morning. Everything looks great.

I've got some fabrication to do before I can start assembling, and it will be a few more weeks before I get my transformers, so that's gonna drive me nuts!

Thanks, Scott for making this available to everyone. I'm really looking forward to getting this up and running.

 

[scott17]

Input/Output Measurements

I have attached a chart with input/output voltage readings taken for this amplifier. I took readings for both 8 ohm & 5 ohm loads in both the triode & UL modes. The input and corresponding output voltage readings were taken at the level right before clipping of the output waveform. The volume control was set for minimum resistance, fully clockwise. The input signal level was adjusted on the function generator. The output readings were taken across the speaker terminals. Resistive dummy loads were used on the amplifier output.

 

[noodle]

Any update on the availability of the full kit??

 

[scott17]

The final shipment of power transformers will be delivered tomorrow. The chassis were supposed to be shipped the week of 1/24/10. I'm hoping to have them at least by the first of next week, then I'm ready to ship.

 

[scott17]

Update

I have sold 3 of the 10 Basic parts kits I currently have for sale.

25 Master Kits will be available for sale starting 2/7/2011.

 

[scott17]

Ready to ship

All chassis and transformers are now in stock and 25 Master Kits are ready to ship. I also have 6 Basic Kits remaining.

If you would like to purchase send a PM and include your PayPal email. If you would prefer shipping to an address different then on your PayPal account, please include so I can calculate the correct shipping charges.

If shipping to the US, the Master Kit is shipped in 2 boxes. One 20" x 12" x 5" @ 9 lbs, and one USPS Priority Mail large flat rate box for the transformers.

If shipping out of the US, the transformers will be shipped in two USPS Priority Mail medium flat rate boxes due to weight restrictions.

The Basic Kit is shipped in one USPS Priority Mail medium flat rate box.

I have attached a photo of the pre-punched chassis that is included with the Master Kit.

 

[skippyboy]

Knock on the the door, postman standing there with a box, all the way from America.
The KT88 kit has arrived intact and it's like Christmas, i must say i was impressed with the packaging, the documentation and the quality of the componants. Well done Scott i don't think i would have taken on such a task like this. I can't wait for your next project, "hint" 300b amp sounds good.
Rob

 

[MashBill]

I too came home to find that the Postman had rang....

He left me 2 boxes. I tore into them like a kid at Christmas! Man this amp has enough iron in it to make a small anvil! I thought the smaller box might just be an anvil.

Seriously, Scott did a great job packing the Master Kit. Everything arrived in perfect shape. I can't imagine how long it took him to put these kits together. Wow! All the various parts and hardware all nicely sorted into various ziplock bags.

Now I have a small problem... I'm itching to start assembly, but I need to paint the chassis first. It's been running about 5 degrees F (-15 C) here and my friend's shop isn't heated well enough to get to the 70 degrees F (21 C) needed to do a good paint job. Why does it need to be so damned cold? Mother Nature is once again jacking up my plans.

I think I might take the chassis to a powder coater and go that route. It would probably be a more durable finish than any paint job I could give it. I also need to decide what color to use. The xformer bells look great, so I may try to match them.

So it looks like it will be awhile before I can start in on it....

I will post any progress I make once I get started.

Thanks again Scott for putting this together! I am impressed so far.

Bill

 

[scott17]

Knock on the the door, postman standing there with a box, all the way from America.
The KT88 kit has arrived intact and it's like Christmas, i must say i was impressed with the packaging, the documentation and the quality of the componants. Well done Scott i don't think i would have taken on such a task like this. I can't wait for your next project, "hint" 300b amp sounds good.
Rob

Thanks very much Rob. I did my best to make sure this would be a great kit. I'm actually moving in the direction of a preamp with phono section at the moment, but it's going to be a while.

 

[scott17]

I too came home to find that the Postman had rang....

He left me 2 boxes. I tore into them like a kid at Christmas! Man this amp has enough iron in it to make a small anvil! I thought the smaller box might just be an anvil.

Seriously, Scott did a great job packing the Master Kit. Everything arrived in perfect shape. I can't imagine how long it took him to put these kits together. Wow! All the various parts and hardware all nicely sorted into various ziplock bags.

Now I have a small problem... I'm itching to start assembly, but I need to paint the chassis first. It's been running about 5 degrees F (-15 C) here and my friend's shop isn't heated well enough to get to the 70 degrees F (21 C) needed to do a good paint job. Why does it need to be so damned cold? Mother Nature is once again jacking up my plans.

I think I might take the chassis to a powder coater and go that route. It would probably be a more durable finish than any paint job I could give it. I also need to decide what color to use. The xformer bells look great, so I may try to match them.

So it looks like it will be awhile before I can start in on it....

I will post any progress I make once I get started.

Thanks again Scott for putting this together! I am impressed so far.

Bill

That's great news Bill. I'm glad it arrived safely. Thanks for the positive comments. I'm looking forward to you getting it up and running. I really believe you are going to love this amp. If you do decide to match the end-bells the color is RAL9006.

Scott

 

[REDHORSEMAN]

Hello everyone,
I guess I have to put my 2 cents in on this kit,
First I have to thank Scott for going to the trouble of putting this project together.
I received my master kit last week and I am very pleased with my purchase, I am not a stranger to kit builds I have built several tube amp kits over the past few years,Three Bottlehead kits and a pair of oddblocks to name a few.
I find this kit to be on par with those kits,very well packed and a exactly what Scott has presented in this thread.
Excellent instructions and a all together well executed project,Well done Scott!

 

[scott17]

Thanks very much for the comments REDHORSEMAN. I'm really looking forward to one of the purchasers of this kit to complete the build. I believe you are really going to like this amp.

 

[REDHORSEMAN]

Mines done and sounds great
This amp is built like a mack truck!

 

[scott17]

That's great! Can you offer any comparison of sound of this amp to the other tube amps you have built? What loudspeakers are you using?

How does your build rate as far as audible hum & noise? Just curious if it is as quiet as mine.

Thanks, Scott

 

[REDHORSEMAN]

I have just an hour of listening time with this amp so I haven't criticly compared this amp with my other kit amps.
The speakers I used are frugal horns that I purchased as a flat-pack with a pair of enabled fe126 fostex drivers,the bass is augmented with a pair of subs.
As far as hum and noise this amp is dead quiet to my ears
I would like to put together some new speakers for this amp any recomendations welcome




Bob