randytsuch
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Posts posted by randytsuch
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If you would not have posted about it, I'd have never known the PS board was supposed to be thicker.
So no problem for me either. A little board like that will be plenty stiff at 062
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paid
Thanks for doing this
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Please add 2 GRHVxxx bare boards to my order, in addition to the 2 assembled boards already there.
Thanks
Randy
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Way overdue update on my 45 based DHT headamp.
In breadboard state, was really quiet.
After I boxed it up, as shown in the pic I posted way back, I had 60 hz humming. It was pretty bad on my hd800's.
Spent a long time trying different things, because quiet a bit of the wiring changed when I moved into the chassis.
It turned out that what finally resolved the problem is that I had added a CLC filter on my ac in line. The filter and ac lines were under the output tx's. Should have been obvious in hindsight.
Removed the filter, ran AC directly from IEC jack to power tx, and noise is almost gone. There is still a real small amount of hum I can hear if no music is playing, but you have to listen for it.
I am using the low impedance output tap from my output tx's.
So in summary, I was able to make a one box dht amp using 45's and the Tubelabs SE pwb that is quiet enough (although I can't call it dead silent). Sounds really good (IMHO).
Randy
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22 hours ago, n_maher said:
It takes ~10-12 seconds to start flowing. I haven't timed the flow, but will at some point soon. It's also doing pre-infusion during that time.
It has settings for both singles and doubles. Both come up short on the first run. The single is what I stated before, add an ounce for when I run it on the double setting. And I'm using a relatively dark roast (Old Bisbee Bali Blue) as it's what I had on hand. I don't tend to have multiple beans at any given time because I'm the only one drinking it and I don't want it sitting for months. Not sure what I'll do for the next batch of beans.
I always weigh beans for each shot, and then time the shot. I aim for about 30 secs from when I push the button, so for pre infusion maybe a bit longer.
Bought a little cheap gram scale just for weighing shots, and made a little arduino to measure grouphead temps, and I added a shot timer function to the arduino. So in daily use its pretty easy for my morning latte.
For bean storage, I think I said this already, but I vacuum pack in about 1/2 lb per and freeze my beans to keep them fairly fresh. I buy 5 lbs at a time, and it takes a few months to go through it.
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Anyone still have boards?
Decided I'd like to give this a try if I can get my hands on the boards.
Randy
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In case anyone still cares about coffee storage, I buy a 5 pound bag from redbird, then separate into bags of about 1/2 pound each.
Then I vacuum pack and freeze the bags. Pull them out as needed, let come to room temp, open and enjoy.
I either pull one shot or make a cup of drip on most mornings, so it takes me a while to go through 5 lbs.
Not as good as freshly roasted, but still pretty good. Once in a while a bag will lose its seal so I pull that one out first, but most stay sealed until I'm ready to use them.
Randy
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Just looking at the circuit, I find it hard to believe the actual values are that critical.
My hunch is since its balanced, they really want sets of resistors to be close. For instance, I could see how R1-R4 should all be close to each other, but I don't think it would be critical they are all close to 750 ohms.
And in the end, the op amps may be what limits performance, not the resistors, but that is also just a hunch.
But because I'm anal, I will usually buy extra resistors and hand match, unless I'm using expensive exotic resistors.
Randy
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FWIW, Allo used the Sparkos discrete op amp design in their Kantana Dac.
From following really long Allo thread at diyaudio for a while
https://www.diyaudio.com/forums/vendor-s-bazaar/294940-fifo-buffer-rpi-sbcs.html
it seems that Allo does a lot of work on their designs, so I expect they tried a lot of options before picking the Sparkos.
I also think I've seen good things about their voltage regs, but never tried them myself.
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If you're in the US
Reviews are mixed, but it is cheap enough to try.
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I ordered from Massdrop a little while ago, and it arrived earlier this week.
Fired it up last night, and right out of the box sounds pretty good.
Letting it burn in now, will see how it sounds tonight.
My initial thought is for a set of cans and amp, its a bargain at the massdrop price.
My long term plan is to build an amp for it, which hopefully I'll be able to get done one of these days.
Randy
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9 hours ago, HemiSam said:
Stunning work, especially for early in your journey. Congrats!
My first proper humidor was made a long time back for me of birdseye maple and Australian paduk. Something about wood boxes that makes me smile...
HS
Thanks. I did take this on later in life, so although a first big wood project I have lots of experience building stuff.
I have a scrap piece of paduk, and am thinking of trying to make a volume knob with it. Hopefully I can make something nice looking.
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35 minutes ago, swt61 said:
Beautiful wood work! The Lacewood looks great with the Quilted Maple! Nice dovetails too!
Thanks
I'm really happy with the final result, but it took MANY MANY hours to get there. My first big woodworking project, so I had to learn as I went.
For both the maple and the leapardwood, I took small pieces of wood and tried a few different finishes, to see which finish came out best. Did a lot of research online on finishing maple when I was working on the main body.
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My chassis is almost done now, finally.
Took a quick pic this morning, lighting not good, but will give you an idea.
The front accent pieces cover a drilling mistake lol.
I tried to add a pic of the top, but I think I reached my size limits for uploading pics maybe?
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16 minutes ago, jose said:
I always use an ATH or a Grado even if the amplifier is not intended for them. If you have any noise, those cans will tell you.
About the output. How do you select the secondary that you are going to use? It is not appreciated very well. Do you have a kind of selector?
I have a limited selection of cans, no grado's and no AT's. I could connect IEM's to the amp I suppose.
In the picture I posted above, you can see red back of a double pole switch on the far right. The output transformers are to the left of that, laying on their sides, and the headphone output jack is just below the switch. So the switch is wired between the output transformers and the output jack.
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55 minutes ago, jose said:
You should try the most sensitive headphones you have ... or at least that's what I usually do.
The only cans I plan to use with this amp are the hd800, he500 and alpha dogs. Of these, the 800's are the most sensitive and I heard hum with them before adding the 2nd inductor.
Based on psud, adding a LC stage knocks the ripple way down, and based on what I hear I would have to agree.
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For anyone following my project, I added another inductor and cap last night.
So now I have a CLCLC filter for B+. Inductors are both Triad C-14X, 6H, 150 ohm, 200 mA. Caps are 1uf, 47uf and 100uf right now. B+ is now around 290V.
So I added the 47uf cap and 2nd inductor. Didn't measure AC ripple before. I tried with the meter I have on B+, but it gave me an ac number I didn't believe, hundred of volts.
But my subjective take is that noise level is down. I tried with HE500 and HD800, and with both background hum is gone. I heard a little noise, but I'm pretty sure its from the tubes I have installed, going to swap them out and see if that fixes the last bit of noise.
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46 minutes ago, sbelyo said:
If I remember it was from knowledge only. I was going to build it around the same time frame you mention and at that time I don't think there was anyone using it with headphones. I bought the custom iron, the board, and all components and then wound up selling the board and components to fund other projects at the time. There's a TSE 2.0 board coming soon so I think I'll revisit this.
Definitely keep us posted on your efforts
I don't remember ever seeing anyone say that, but can't read all the posts lol.
Yeah, definitely not a lot of headphone TSEs out there that I know of. Think there are more of the Tom Christiansen 300B Amps, but that's a more expensive build.
I'll see if I have time to play with the B+ filtering soon, but trying to finish the chassis and the NCAA tourney are taking up most of my free time right now lol.
A VERY preliminary version of my site for this build
Really need to add some pics to it.
Randy
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This is what I built.
Since 45's run on a lower bias current, an output tranny for a 45 amp is cheaper than a 300b tranny, so while the iron wasn't cheap, it wasn't as much as I thought it would be. I bought the low imd version, which adds a bit to the cost. He wound quickly too, my iron was delivered to my house a week after I paid for it.
Its their DHT board. Does take some research and figuring stuff out, because it supports different tubes you need to pick a tube, and then pick the iron and some other parts based on your tube.
EDIT: He's revising the TSE to replace obsolete parts and make some other tweaks, I don't think the new board is available yet but it should be out pretty soon.
BTW, one other "problem" I had. When I was swapping rectifier tubes soon after I got it running, I accidentally hit the switch to use the 300 ohm secondary. When I listened to my he500's like this, amp would distort when playing louder passages in a song. I thought somehow I had broken something, until I figured out the switch was in the wrong position. All good when I switched it back.
I running it at a relatively low bias, around 25 ma. If I upped the bias, should put out more power before it distorts, but I don't need the power as long as the switch is in the right position lol.
Randy
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51 minutes ago, sbelyo said:
I had acquired all the parts to build one except for the power transformer. I too have a set of electraprint output with a 5K primary and 32, 80, 120, and 300 secondaries. I sold the board and components but kept the OPT's and the 45 tubes. Someone on DIYaudio had said that the secondary values I chose would be too noisy for headphones. How does it sound on the 64 and 300 ohm taps?
So build is only a few weeks old, and still in flux.
I've mainly been using my he500's and the 64ohm taps, and it sounds great (IMHO). Might be my new toy bias, but I'm happy with this combination.
Somewhere else I saw someone say 45's and orthos make a good combination, and based on my amp I'd have to agree.
With HD800's and 300 ohms, there is some background noise. I think its coming from my B+, and I bought another inductor to make a CLCLC filter for B+ to knock down the noise. To get B+ down to 300V, I'm using a pretty small cap for the first C, 1 or 2 uf. This lowers B+, but makes more ripple than if I had a larger cap here.
I'll let you know how the 800's sound after I add the 2nd inductor. I also have a different rectifier tube to try, got it last week, GZ30. It would be underpowered for a 300b amp, but should be fine for a 45.
Did the diyaudio person tell you about the noise from experience, or from "knowledge"? I'm not sure why those taps would be noisy?
What cans are you using?
BTW, I actually started this build maybe 5 years ago. Researched, bought the TSE board, and most of the parts. Even stuffed the board for the most part. Oh, and did a not of work making custom heat sinks. But I couldn't decide on the output tx, and wanted to be able to use either 300b or 45's and wanted to have a 2 chassis design. Made it too complicated, so I just pushed it aside lol. Resurrected beginning of the year, bought the electraprint iron and a few other bits and pieces, and got it running. Really glad I did.
Randy
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Thought I would share a pic of my current project as an introduction, since this is my 2nd post here.
The board is from Tubelab, its his Single Ended board, so this is a TSE amp.
For you purists, it uses sand for a current source, they are under the board so you can't see it in the pics.
Big tubes are 45's, driving Electraprint output iron which were wound for headphones, 5k@50ma with 46 and 300 ohm secondaries
Edcor power tx, 5V4 rectifier into a CLC filter for B+ of 300V, and for now, a fairly simple DC reg for the DHT heater power.
Working on its chassis now, a wooden box made from curly maple. The TSE pcb will be under a fiberglass plate that is all drilled out and ready.
I have a few other coupling caps I will try out, see what I like the best.
I also have a Coleman DHT filament heater that I am planning to use to drive the heaters in the 45's.
I'll also have a wiki page at some point soon, with more details on what's inside and how it was built.
Randy
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2 grhv, 1 grlv78xx, 1 grlv79xx, 1 main board, 1 mini t2 please
Thanks
Kerry Design mini GRHV\GRLV and JoaMat mini T2 Group Buy
in Do It Yourself
Posted
My boards came over the weekend, thanks for doing this.