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Very quiet and clean. Powers Klipsch Lascalas nicely. I didn’t find the bass muddy as others have. It does run quite warm but is, after all, a class A amp. Do remember that it has no speaker protection.

I live in the UK, the transistors and boards arrived within two weeks. The build was straight forward and housed in a 4U Galaxy case. The two 500 VA transformers are bolted the the front panel. It’s not pretty but it’s functional. Unfortunately the build guide called for the bias and offset pots to be rotated fully anti clockwise before power on. At power on the two boards fried themselves with added dramatic smoke. The penny dropped, maybe next time I’ll ensure the pots are fully clockwise before turn on. I replaced two blackened resistors on each board and ordered a new set of transistors, just to be on the safe side although the previous traumatised ones tested OK. Second power on no smoke or blackening slowly increased the pots counter clockwise following the build guide to 0.59 volts. Heatsinks about 50 degrees C when stable. It sounds fantastic. I was so impressed I have since ordered the boards and transistor kit and built an F5 Turbo in a 5U Galaxy case. which sounds about the same but slightly more dynamic. The bias issue was not a problem with the Turbo as you set the bias pots to full resistance via test points. Prior to switch on. Two superb products that sound amazing. I’m presently building a Pearl 2 Phono stage from Pass DIY. Thank you Nelson, Wayne and all the team at DIY Audio.

I've been a HiFi/audio repair tech for many years and have heard tons of pieces in that time and this is easily one of my favorites. Been listening to it mostly through my full range with subwoofer assist tower speakers I built myself. I'm a big fan of simple circuits so this design is right up my alley. On my build, I simplified it further and replaced the volume pot with fixed resistors, wired the input jacks straight to the tubes, and bypassed the headphone circuit as I don't need any of those features. The auto bias circuit is definitely my favorite part of this amp; love being able to just jam some glass in and go. The build was super easy for a seasoned pro, took me just under 6 hours with a dinner break and everything worked on the first try as the directions are pretty good. I had the luxury of bringing this up on a variac and I don't even wanna think about the terror of just "flipping the switch and see what happens." Handles pretty much anything you put through it. The stock 6L6's sound decent, but it really excels with KT88's.
In conclusion, it's a simple circuit, easy build, elegant hardware design, and sounds like it should cost far more than it does. Great amp.

The completed amplifier runs hotter than I would have thought, but it stabilized after the first hour. I'm using the Meanwell 24v switcher and the power supply seems electrically quiet.
It sounds great with no noise or hum, except during power up and shutdown.. but nothing I have a problem with.
All in all, a very nice project.

When I bought my first Deluxe 5U chassis I was surprised at how big it was. It makes the Deluxe 4U chassis look like mini-me in comparison. However, it turned out to be the perfect size for a big class AB stereo amp or a First Watt style class A stereo amp with the bias cranked up. It has enough space to lay out a fully dual mono power supply with separate transformers. The heat sinks barely get warm when housing a typical 200 watt class AB amp.

I recently bought a second chassis to make Aleph 2 mono block amps. The heat sinks are able to handle the dissipation, but they do they get very hot. I guess the chassis is not too big after all. The entire chassis gets hot. I imagine my two cats will love them come winter. This latest version of the Deluxe 5U chassis now has machined screws to hold on the top plate, which is better than the first version I bought a couple of years back, because the rail holes wont strip if accidentally over-tightened. The only negatives were that the proper size screws to hold the feet on the bottom plate / rail were not included, and if you buy handles, you have to widen a bit of two of the pilot holes, because the screw heads that ship with the handles are just a little too wide to fit into two of the four pilot holes that are machined into the face plate.

All in all a very nice chassis.

Great Kit it all worked first try. It's a great price and you know you get genuine parts. So highly recommended!!!

This is the second set of binding posts. The first set I used on a F5 Turbo V2 clone and bought with the rear panel accessary kit. I like these so much I bought these for an Aleph Classic I am building now.

I already bought many of these enclosures. They all work great and it is a pleasure to install the amps I designed inside them.

They have a good dissipating characteristics.

Extremely recommended.

Walter

Was surprised how well this works, bought several, used one on my 6-24 crossover. To my ears, bass has more authority and image is more vivid . Will try the other on the Korg B1. Going to get 2 more for new projects. Highly recommended

These LSK170 were intended to replace 2SK170 for the realization of a RIAA PACIFIC preamp. The result is excellent.

I finished the build and the sound is superb. The best result is after 100 hours of break in. The imaging,clarity,separation and soundstage are excellent. I used the Sophia Electric KT88 power tubes with Tung-Sol 12AT7. Also the coupling caps was upgraded with Audio Note Copper Foil Film Capacitors and Signal path I replaced it with 1% Takman Metal film resistors.

A great little preamp.
Stayed as main resident, with an F4 amp. and an F5.
In the future it will not be easy to make improvements.

The Jfets perform great and are well matched. Delivery from the DIY Audio Store is prompt as well.

Purchase was easy and shipping fast. Thank you! Could not yet use the JFETs and hopefully will get the Mosfets for the ACA mini too;)

I'm putting together an all tube system to go with my Bob Latino VTA ST-70, this was the perfect addition. The kit was VERY well put together, amazed by the quality of the parts and the engineering. Worked on the first powerup (always a bonus). I have not done any modifications, though I did swap some tubes around to see the difference in audio. This one is a definite keeper and should last several lifetimes.