DIY Audio Projects Forum

Well I don't want my amps frequency response to look like a guitar amp that's for sure!

If anything I don't care for extended top end response but I personally want the low end, maybe not flat to 20Hz but at least flat to 40Hz. I know I wouldn't be the only person that finds -3db at 46Hz unacceptable. The SET amp I use currently with my horns goes down flat to 30Hz and it's perfectly acceptable to me but might not be to someone else. Like I said it depends on the speaker and the music you listen to, if -3db @ 46Hz is adequate for you then c'est la vie

The CCS idea was just an idea, I know some people are dead set against them for some reason or another. I was mainly just suggesting using a cathode bypass cap and see how much gain you get, maybe there is enough to add a bit of feedback. In the land of DIY people might want to pursue some modifications, seeing how everything is subjective their views may differ from yours and like the amp with a bit of feedback.

Like I said the CCS was just an idea, I have used them on numerous occasions and personally not once heard anything dissonant. I would suspect any audible different to be the reduction in distortion. From an AC standpoint the CCS plate load looks like a very high impedance making the load line horizontal.

I've used the IXYS 10M45S / 10M90S as plate loads in a few recent projects, and I like them Very easy to wire up, and they sound good to my ears (that's all I care about)
In comparing them with a resistive plate load, I found I was able to get a bit more voltage swing out of the triodes I was using in my particular applications.




That doesn't sound very scientific What's wrong with forcing the operation of a device using feedback?
I'm just bugging you.. I've just come to expect incredibly detailed / calculated reasons for your design choices with amplifiers. But I do definitely agree that we're always after "what produces the most pleasant sounding piece of equipment"

How do you think this compares to the Little Dot MKII? I am thinking about either trying to build this amp or just buying the Little Dot for my HD650.

I'm going to dive into this one, because it looks like the perfect place to get my feet wet in building something from scratch with a pile of parts. The chassis will be relatively easy for me to build, but I have a couple of questions about sourcing parts - or maybe I should say what the parts are called..

In Matt's photo's I can see these little standoffs attached to his upper lid, which he uses as ground points and terminal points for other runs.. What are those called? That would've solved a number of issues on the last project I tried. To me they look like micarta blocks with a run of copper or tin along them to solder to... if I knew the name of them, I could find them.

I'm hoping this will be the perfect compliment to my home office, either pushed by a Rockbox ipod, or my computer sound card to some decent bookshelves. I'm way past the boomy fake bass speakers that have sounded bad for the last 3 years in there. Please help me out with the name of those terminal strip things so I can get the parts on order!

Mack

This is a speaker amplifier and the "Little Dot" is a headphone amplifier. Since you reference Sennheiser HD 650 headphones, I wouldn't think this particular amp is appropriate.

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Matt
It's all about the Glass!
http://www.CascadeTubes.com
Cascade Tubes Blog

They are called X lug terminal strips, where X is the number of lugs.

https://www.tubesandmore.com/products/t ... horizontal
ebay as well.

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[ DIY Mains AC Power Cable Cord ] - [ Gobo LM1875 Amp Kit ] - [ Tang Band D4-1 Horn Speaker Kit ] - [ Monoblock Push-Pull KT88 Tube Amp Kit ]

Thanks Gio.. because I had to wait for my post to get approved, I wasn't able to say that I'd actually found them on several sites. I guess I didn't search hard enough before asking!

I finally got around to building this little amp. I planned on building it a few months ago but got sidetracked on other projects. I made a few changes, I used a TriadMagnetics C-14X choke and chose to use some 100 ohm resistors in place of the other 2 chokes. I actually have the other 2 chokes but I wanted to conserve some space so I decided to see if the resistors were good enough. The amp is plenty quite enough even with my 103db horns. I also used a .1 uh coupling cap instead of Matts recommended .01 uh. My OPT's are some Edcor XSE15-5K's which seem to be a good match with the power output of the amp. A very nice typical SET sounding from the start with no hours on the tubes. I only expect it to get better. About as simple tube point to point build as you are going to find and the cost is about as low as it gets as well. I can see this amp going together with a good 90db or better full range speaker for some outstanding sound for not much money. Do not expect to rock the house but the quality of sound is outstanding within its power limitation.

Hey Suncalc. Thanks for the project post. This is going to be my very first tube amp project! Cant wait.

I've had the Vertical Amp in my office at home for the last month or so because I had a 6CY7 fail in this amp and didn't have a replacement. Well, I've received my replacements and this little amp is back in fine voice, singing in my office as I work away.

For such a simple little amp, the unit really does have a very fine sound. And the depth of the soundstage is really excellent.

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Matt
It's all about the Glass!
http://www.CascadeTubes.com
Cascade Tubes Blog