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Egh scratch that last question.
Toying with the idea of upgrading my amp since my STBXW got the good amp in the divorce. Any recs on a good, extremely low wattage amp? I don't need a lot of watts. Like 3wpc at the most.
Basinbeater or Thom...any reccs?
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You're gonna need all that bass!
You could build your own tube amp. You are a capable fellow, build your own...
https://bottlehead.com/product/stere...rated-2a3-amp/
3.5wpc i believe? $1200 or so?
Hmmm what do I need? Soldering iron? Anything else?Quote:
Originally Posted by basinbeater
Any estimate on how much time this would take?
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Also how do I evaluate different amp designs?
This would be the other contender that I've found:
https://diyaudiostore.com/collection...l-transformers
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Quote:
Originally Posted by tgapp
For a 3ish watt output you can probably afford the inefficiency of a Class A amp for less $$ bro.
Might pull 20w to make 3w, but the standing draw will be half that. Maybe half an amp.
And a pure sine battery backup will make anything you plug into it sound gooder, run cooler, last longer than straight wall power. A lot of ppl never even contemplate how crappy their home electricity is until they get picky about transformers and tube biasing, or get into some other electronic project. [Pure sine battery backups make hard drives last longer too...]
The amp I linked is a single-minded triode (class A) amp, but the pure sine battery backup is a great recommendation.Quote:
Originally Posted by highangle
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People seem to really like the elekit stuff; it would be fun to make the 300b kit at some point.
If you can wait, the decware zen triode is supposed to be incredible and is relatively affordable. They never seem to show up on the used market, so people must like them. The catch is that the wait for a new one is close to a year usually.
For the music I listen to it seems like push/pull tube designs suit me better than SET design, but it would be fun to compare them at some point. I certainly have speakers that are efficient enough to work with SET.
Nice yeah I've thought about an Elekit 300b amp, but that might be out of my price range for the time being. Right now I am running an AppJ Miniwatt 6n1 + 6j1 amp, it's decent, but I definitely have upgradeitus.Quote:
Originally Posted by jorion
Thinking about this amp now:
https://glow-audio.com/collections/a...tube-amplifier
It's point-to-point, got great tubes, and comes with a 24kHz DAC. What am I missing here? $680 feels like a steal.
The 6moons review is very positive. Looks like a great value for sure. Seems that it’s so cheap because it’s made in China and direct-to-consumer. People turn up their noses at Chi-Fi, but it’s the only way you’re going to get a new amp at that price without building it yourself.
Caveat: I haven’t listened to any of these.
Note that the Mullard el84s are the new Chinese tubes that have nothing to do with the old school Mullards. So the tubes in it are not that special.
Yeah, I guess my question is - do I buy the chi-fi amp for $700, or look at an amp kit in the $1200 range?
I definitely don't need more than 5 watts. Hmm.
Have you looked at PS Audio’s Sprout 100?
I have, but it has more than I need - 50wpc, bluetooth receiver, good DAC - I have a great DAC and a receiver (as well as a turntable and a good phono stage). I need a minimalist amp.Quote:
Originally Posted by Flyoverland Captive
Leaning strongly towards the GLOW Amp One, even if the Mullard teams are not that special.
Schiit Vidar or aegir?Quote:
Originally Posted by tgapp
So I always read this thread with interest as I try to learn, even though I haven't invested anything yet. Why only 5 watts? Super efficient speakers? Is there any downside to having more than you need wattage wise?
Yep, very efficient speakers, even then, a majority of the listening normal people do with less efficient speakers rarely exceeds 5+ watts. So efficient speakers and a low powered amp should get to perfectly loud listening levels.
Single ended triode circuit topologies do not produce a ton of power, but introduce a certain tube distortion that many people find very pleasing to listen to.
Lolly lolly I'm a fkn idiot...and this after I saw 3 output modes in your link.Quote:
Originally Posted by tgapp
Anyway, you'll lose some power factor in a sine wave backup, which will add to your dead draw and maybe bring it up to something like a compact fluorescent bulb...
In a Class A amp, yes, because they draw power when they're on. That's the limitation of Class A - hard to scale up without hudge transformers and tubes and 50s-style power requirements. And since your tubes are your primary power modulators and amplifiers, they make a big difference in how the amp sounds. Tgapp can swap those long plate JJs out of his linked kit for some Sovtek [what's in a new Macintosh], or Chinese Genelex Gold Lions, or some others he may like better.Quote:
Originally Posted by zion zig zag
And speaker efficiency is measured by how loud it will produce a test tone into a test mic at 1m distance. The venerable Klipschhorns will make something like 110db with 1 watt input, which is very loud...
Contrary to some, I don't think there's much percentage in trying to create a reference amp with consumer hifi gear, especially if one's room is super reflective or otherwise less than optimal. All amps are going to "distort" a frequency reference curve, so does the human ear. You want your distortion to be musical and fluid so it doesn't detract from the source signal. Best way to do that is with natural sine waves with the distortion concentrated in 2nd and 5th order harmonics, which makes a source sound "bigger" and "cleaner"... And no matter how digital your system is, your speakers ultimately move air to make round waves humans evolved to hear and not square ones best suited for pulse width modulation.
Whelp, I’ve got another guitar amp issue. Solid state Marshall amp head with a preamp tube. Grounding problem. Bad hum and distortion when it’s plugged in. I think it’s a straightforward fix but I don’t have the skills. And it’s not worth enough to take it to a shop and give them $200 to maybe not fix it. Anyone on the front range and wanna fuck around with looking at it, or anyone know a person or shop around here that would do it for some side cash?
Copy on the above explanations, thanks.
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Quote:
Originally Posted by EWG
60-cycle hum? Could it be your jack? Power cable? Leaky cap? Power supply?
have you tried hitting it with a stick? that's what Dimebag did...
Does it without the patch cable plugged in so probably not the jack. Took out the preamp tube, still humming. Changed the power cable. I'm guessing cap.Quote:
Originally Posted by highangle
And of course I tried hitting it with a stick. That's my big move. Maybe I should get a bigger stick?
Short the inputs to the power amp section. Still get hum? Do you have a scope?
And everything you just wrote is totally Greek.Quote:
Originally Posted by basinbeater
No I don’t have a scope.
Plugging a guitar into the FX return does not impact the hum/buzz. From some research that seems to mean that the problem is in the power supply or power amp. Does that sound right?
Buzz is the same coming through headphones when I plug into the headphone Jack.
One other clue - when I turn the amp on the buzz/hum comes on, and after a few seconds it gets much louder, then drops away for a few seconds back to that original volume.
So the hum doesn't change with volume up/down? Do you have an effects loop and is it switchable? Sometimes they cause issues.
Inspect any case/frame/screw grounds that might be faulty. Find the power supply filter caps, if you can, and see if you feel up to replacing them.
Give any shop all of your observational data. Get an estimate. You may have a disposable amp.
Effects loop is not switchable. Volume doesn't change the hum.Quote:
Originally Posted by highangle
I'm thinking it might be the filter caps. Some local shops are telling me it'll cost between 100-200 most likely. I think it's probably not an option at that cost.
Meanwhile, a bag of Sanyo or Nichicon caps prob cost $3 on Ebay. No-clean solder's pretty cheep too. You can usually look up your existing cap specs by the codes on the side.
https://www.electronics2000.co.uk/da...f/capmarks.php
https://www.electronics2000.co.uk/ca...calculator.php
Thanks. I know literally nothing about this, but I may keep it around and fool around with it. To great frustration I'm sure.Quote:
Originally Posted by highangle
Progress: Maybe there's more screwed up, but the hum is definitely coming from the filter caps. One of them is loose. If I move it around (to a pretty extreme angle) it makes contact and the hum goes away. Nice!
Except I have no fucking idea how to change a filter cap.
EDIT: well. I pulled the board, flipped it over, ham-handedly soldered the loose cap back on with a way too big gun and solder, probably barely connected it, put it back together, and it fucking works! Still get a bit of hum cycle-up and then drop away at start up, and still some static sometimes when no guitar is plugged in. Maybe just need to clean out input jack to get rid of the static?
Either way, pretty pumped!
Woot! Congrats on a successful re-flow!
You can pick up decent solder workstations with hot air and iron and an assortment of different tips for less than a C-note. Some will come with forceps and tweezers and mirrors - just about all you need for component swaps and buildouts.
A modern countertop convection oven can flow whole boards with paste solder. Paste and stick components on board. Pop board in oven. Heat to X temp and then turn off and cool down. When it's done, you have a populated board.
With a hot air wand, you can dab no-clean paste on with a toothpick, and flow tiny little components with a tiny little jet of air at just the right digital temp. Or you can heat & flow entire regions of a board at once with wide flat tips and more air.
Do you have a remote thermometer? They're great for finding faulty FETs and caps and resistors - one will be noticeably warmer than the others. That's typically how hard it is to diagnose a faulty MOSFET in a vintage receiver...
The Bob Noyces and Andrew Groves and other pioneers of electronics grew up on farms. Electronics is mostly common sense, and a lot more approachable than most ppl think.
Anyone with a preferred adjustable temp, bench top soldering iron? Almost all of my electronic experience is with mil-spec equipment from the early NASA days.
Right channel cut out on the hifi. One of my planned projects for this winter was to clean and replace circuitry from the 70s/80s. Looks like the timeline has moved forward.
Horowitz & Hill has been moved to the coffee table. Will be dropping hints to the wife that all I want for Christmas is an oscilloscope.
I use a hakko fx888d. I love it. https://www.hakko.com/english/produc...ko_fx888d.html
And for scopes, i think it is tough to beat the rigol $400 machine...
https://www.tequipment.net/Rigol/DS1...Oscilloscopes/
Hakko is a good brand...You prob want hot air too - "SMD Rework Station".
You may find you don't need to pay for pro-tier gear if you're not using it every day or week. These are not complicated machines.
Most of the Chinese stations that cost half or less of Hakkos and Wellers will last you a few years. Some are even cheap enough to buy for one or two jobs.
Tin the tips well, and they'll do a good in a wide variety of tasks. Zon and Ebay have most anything electronics. Ebay is a source for small quantities of pretty much any component you can spec, and old used and NOS shit too.
I've bought enough fake shit on eBay, that i discourage that path. Don't support the intl scammers. I do buy lots of stuff on eBay, but not electronic components. Don't support a Chinese ripoff of the hakko. Buy the good shit once, and have a decent seeing iron the rest of your life.
I've done lots of electronics repair and building, (i think it's fun), and i have yet to need a hot air rework station.
Just my experience.
I've heard decent things about the PineCil or TS80/TS100 for a portable unit. USB C PD seems like it could be good depending on your needs and other equipment. I think you probably could solder with power from you laptop, but I have been avoiding keeping up too much with the PD versions so I'm not certain. They are cheap enough I might pick one up, I figure it costs me ~$10 to go to my office to solder something if I didn't have a reason to be there anyway.
I had an HSU Research VTF-3 Mk2 fall into my lap for free because it sounded "wrong." I hooked it up with the line level inputs (for some reason I don't have any subwoofer RCA cables around) and sure enough, it sounded muddy and scratchy but definitely had power. I pulled the amp plate and didn't see anything obviously wrong. I pulled the woofer and the cone and surround is in good shape, travels smoothly, and moves well with a 9v. I put a multimeter on it and it tests at 2.5ohms and rises to about 3.2ohms.
I'll try with the low level RCA inputs soon, once I can snag some cables. I don't know quite enough about this stuff to diagnose much more in depth without advice. Any words of wisdom?
Woosh. Really fell down the rabbit hole. KSL has been a source of great deals and met some interesting folks.
I picked up a Fluke DMM and probe master modular probes after finding my cheap meter bit the dust.
Next was an Aixun JBC copy after reading around eevblog. I agree with basin about not supporting intellectual theft but it’s a hard pill to support a $500 machine that fundamentally hasn’t evolved for a decade plus. I have been using the genuine JBC tips. Will need to replace the Chinese caps in the power section and add ESD protection at some point. Will most likely modify the iron stand to pass power to the handle at the same time to clean up the cord routing.
Have started cleaning 40 years worth of crud and am going to do a full recap on the preamp. Regulated voltages are a little funky so will check semiconductors after replacing electrolytics. Hoping to build a diy pcb holder using photography third hand next week.
I have had good luck sourcing solvents so far except DI water. Grainger will sell me a liter for $30 but I am thinking about poking around the chemistry building at the U with a backpack and helpless look on my face. I forgot how nice it was to have free access to those sorts of things.
McMaster carr lists DI water for $5/ gallon, and they’ll give you a shipping quote online now.