SparkFun Electronics Commentsurn:uuid:214d0e4e-f1b1-d287-ce26-ac5b4c9f82492024-03-29T03:14:21-06:00SparkFun ElectronicsTechnick on Tube Amps in the Age of Bluetooth SpeakersTechnickurn:uuid:a4338dc0-85f4-d881-6844-c65bc35f922d2018-01-24T13:25:47-07:00<p>Oh, ok thank you! I will have to do a little research then as to the best edition for both I guess. Yeah, I am sure I will have several pages marked as well, once I get a copy and understand the scope of tubes a bit better.<p>Yes, I know I would enjoy a tube video! Maybe you could talk about this project of yours, play us some of the audio from your amp or something, and explain the design process somewhat after an intro on tubes?</p><p>I actually found a funny, short, old video from Westinghouse on the 6 functions of tubes, and how to use them in each case haha. I would like to eventually build an oscilloscope out of tubes, that is the goal haha. My grandpa has one he built back in the 70s lol. I also, picked up another radio with tubes. This one is Realistic brand FM/AM (radio shack brand), not just AM like the other I have.</p><p>Yes, that is what I meant. That would be interesting to see haha. Oh, I gotcha, I have similar feelings about BT lol.</p></p>
Technick on Tube Amps in the Age of Bluetooth SpeakersTechnickurn:uuid:431a37c4-0863-64c7-eb23-3fec66e4022d2018-01-24T13:16:34-07:00<p>Hum, thank you. I will have to check out both resources when I have a chance!</p>
Tenacious_Techhunter on Tube Amps in the Age of Bluetooth SpeakersTenacious_Techhunterurn:uuid:8067d3a1-d839-d15f-8a28-ec15ee34793d2018-01-14T15:30:52-07:00<p>Pete, you are in a surprisingly unique position to actually <em>do</em> something about these audiofool nutjobs while benefiting the electronics hobbyist community in general. Might I suggest...<p>A Build Your Own Vacuum Tube kit; include a heating element, some electrode material, some glassware, an end-cap with contacts, maybe a punch to put holes in the electrode material for those without a laser cutter, and instructions</p><p>An open-source vacuum tube design that lets you <em>toggle</em> (that's right, <em>toggle</em>) between linear and non-linear response, illustrating the point that even vacuum tubes can respond with precision linearity devoid of "warm sound" response, if you care enough about the details to make it so</p></p>
Customer #52302 on Tube Amps in the Age of Bluetooth SpeakersCustomer #52302urn:uuid:c0e3300a-dd42-ce3f-5c4d-2c2497f5d2e02018-01-14T14:23:18-07:00<p>P.P.S. Another reason to bring the HT up slowly is to the electrolytic caps time to polarize
(especially if the amp has been shut off for a long time). Tubes worked good with tubes--
mixing them with solid state is a tricky business (as a lot of guitar amp designers have
learned the hard way).</p>
Customer #52302 on Tube Amps in the Age of Bluetooth SpeakersCustomer #52302urn:uuid:8728ea5a-6ddf-a51e-34fb-a4f5e21ca2262018-01-14T14:18:11-07:00<p>P.S. Normally there's no DC though the output xformer, so no big field. But funny things happen during
start up, or when speakers are connected or disconnected. Also relays contacts can bounce. All it takes
to get a big voltage spike is to get a field going and then suddenly collapse it. You're starting with 350 VDC...</p>
Customer #52302 on Tube Amps in the Age of Bluetooth SpeakersCustomer #52302urn:uuid:9a62eaa3-7f77-20a9-3c68-4d2cf0685c242018-01-14T14:06:22-07:00<p>Great project. As you probably know, you're getting the pop when the HT comes on because
the HT supply is solid state and comes up in a hurry--no cathod heaters to warm up. :-)
Putting a relay on the speaker connections is a bad idea because of self-induction in the
output transformer. It could easily exceed the max. plate voltage and blow the output tubes
or a cap. One possible solution would be to use a use the regulator to switch on the HT
gradually (say was a capacitor w/bleeder resistor chargers on the regulator input).
Speakers should <em>never</em> be connected or disconnected from a tube amp while the amp
is turned on.</p>
Madbodger on Tube Amps in the Age of Bluetooth SpeakersMadbodgerurn:uuid:a51431d2-7375-f8c9-234e-15f81ffa9e732018-01-12T16:46:23-07:00<p>Back when capacitors were physically large and expensive, the usual approaches to hum reduction were tapped heater windings and big inductors on the HT supply. I wonder if adding inductance on the LT supply would let you get more headroom. Somehow I'm guessing the physics of it would end up dictating an enormous hunk of copper and iron but I haven't done the math.</p>
Madbodger on Tube Amps in the Age of Bluetooth SpeakersMadbodgerurn:uuid:53acf3fd-f8f2-f5b0-130a-7b3f5b9cf0c02018-01-12T16:43:23-07:00<p>As it happens, <a href="www.lectron.de" rel="nofollow">Lectron</a> offers a great set of electronic learning blocks, which include vacuum tube modules. You can even get vacuum tube breadboards from <a href="http://www.ak-modul-bus.de/stat/experimentiersysteme.html" rel="nofollow">Modul-Bus</a>.</p>
john luke on Tube Amps in the Age of Bluetooth Speakersjohn lukeurn:uuid:003159ee-b6bf-b0f2-44f5-9760614894f62018-01-12T15:42:22-07:00<p>I appreciate your comments about the audiophile scams. My favourite was the $10,00 solid silver
USB cable that apparently improves the musicality of digital sound.</p>
john luke on Tube Amps in the Age of Bluetooth Speakersjohn lukeurn:uuid:c4ca1070-b8af-6485-1907-c9e5f9a6b0a82018-01-12T15:35:04-07:00<p>Or if you want really good valve sound you could just buy a pair of old Quad IIs. I believe Quad
have started manufacturing them again in China with modern connectors. Only 15W from a pair
of KT66s (Class A ?) so you need efficient speakers. Goes nicely with a pair of Tannoy monitor
Golds.</p>
Customer #1264733 on Tube Amps in the Age of Bluetooth SpeakersCustomer #1264733urn:uuid:2b8c4cff-e201-7813-9513-63dcc086204f2018-01-12T14:25:54-07:00<p>i look at tubes this way they are not dead there are just misunderstood i am doing the repairs ion a 65 year old Allen organ and it is all tubes and it has a better sound than the solid state one and easy to fix too</p>
Customer #570953 on Tube Amps in the Age of Bluetooth SpeakersCustomer #570953urn:uuid:4287732e-e9c4-f204-c0fd-64a48f6ffe572018-01-09T22:23:12-07:00<p>I once designed a very basic tube amp, using two 50C5s (one for each channel) and a 12AX7. The power supply was solid state (although I almost used a 5Y4 for the rectifier). I don't think I ever finished it, though.</p>
Pete-O on Tube Amps in the Age of Bluetooth SpeakersPete-Ourn:uuid:da1a6315-34c0-8d05-edbc-40d65f4918d22018-01-09T16:18:18-07:00<p>Huh. Well, i guess that's what it takes. Thanks for that.</p>
l0gikG8 on Tube Amps in the Age of Bluetooth Speakersl0gikG8urn:uuid:d7d4e9d2-fe7d-51ae-2f9c-8c07a40498a92018-01-09T15:29:19-07:00<p>With Markdown, the trick is putting an exclamation mark in front of a link to an image<p>see <a href="https://daringfireball.net/projects/markdown/syntax#img" rel="nofollow">https://daringfireball.net/projects/markdown/syntax#img</a> for a better explanation</p><p><img src="http://diyaudioprojects.com/Tubes/EL84-Push-Pull/ECC802S-SRPP-EL84-Push-Pull-Tube-Amplifier.jpg" alt="oddwatt"></p></p>
Pete-O on Tube Amps in the Age of Bluetooth SpeakersPete-Ourn:uuid:f6957acd-6812-d876-26c3-f07c5bd8b4162018-01-09T10:51:36-07:00<p>The books with "Building" in the title cover all the mechanical aspects of tube amps, the ones without cover circuit principles. I've got the first editions of both, don't know what's added for the second. But if you want to learn how tubes work (maybe a video to come?), get one of the editions of "Valve Amplifiers". I've got tons of post-its in my copy marking pages where I spent a lot of time.<p>Add BT? Yeah, sooner or later I'll probably do that. But they'll also be running off my desktop, more than likely, so I'm not sure what the point of BT would be.</p></p>
Pete-O on Tube Amps in the Age of Bluetooth SpeakersPete-Ourn:uuid:80bbf775-dfbe-bbb9-157a-0588f473a7e32018-01-09T09:19:47-07:00<p>I've seen some examples built on 2x4's (OK, I've seen one, not multiple) with everything exposed. I'd never advocate something like that, cuz it's dangerous as [insert expletive of choice]. Everything's got to be secure enough that you can trust it won't ever move. When things pop, I scream like a child.<p>Yeah, I wish we could have pics in here, too. Dunno what that takes. But you can always post a link.</p></p>
Customer #32186 on Tube Amps in the Age of Bluetooth SpeakersCustomer #32186urn:uuid:7d90307f-d8a4-1a00-c6a0-5a1d4ca9d1ec2018-01-09T05:55:24-07:00<p>Nice to see something old-school with no microcontrollers for a change!<p>I really love the layout. I've built a couple of tube amps based on Bruce Perens' "OddWatt" ultralinear design and been quite pleased with the results. However, I used a very conventional layout with tubes and trannys on top and wiring on the bottom. I really like the idea of exposing the wiring, at least for a "shop" system. I may try your approach next time with the perforated plates to mount the tubes.</p><p>It seems I can't embed images here, so no photos :(
Or maybe there is a trick to doing this?</p></p>
Customer #1263225 on Tube Amps in the Age of Bluetooth SpeakersCustomer #1263225urn:uuid:5f40a11e-1ffa-63fb-6661-c79c052492f32018-01-09T03:32:36-07:00<p>The layout of the chassis is nothing earth-shaking. Power (left) and audio (right) transformers are on opposite sides and orthogonal so as not to interfere with each other, tubes are in the middle, power supplies are to the back where I have access to a heat sink, and controls are to the front.This circuit I found pretty nice that PETE-O</p>
Technick on Tube Amps in the Age of Bluetooth SpeakersTechnickurn:uuid:0874b4b8-c4c9-ff57-1ec8-307c30b3d9602018-01-09T01:15:43-07:00<p>So, I am definitely interested in esoterica, such as, vaccum tubes lol, however, I too have a short attention span, and tubes seem quite elusive.<p>I bought an old AM Federal radio, stupidlly expecting all the parts to still be there and functioning lol, and that the radio would somehow transfer the knowledge of its makers design process by osmosis after I cracked the top off lol. Needless to say, this was not the case lol. About all I learned is point to point wiring is a pain to turn into aa circuit, and I am fairly certain the radio has a 3 stage design using 3 different pentode tubes. Eventually, I'd like to restore it one day.</p><p>As far as the Morgan Jones books go, I see four options. So, do you have a recommendation on which book for a tube newbie? I have some electronics knowledge, buy have much to learn in troubleshooting and design. Thanks for your time!</p><p>Can't wait to see the finished project! Have you thought about an external or internal addition to the project for Bluetooth audio? So your speakers could too be "convenient" lol xD</p></p>
Pete-O on Tube Amps in the Age of Bluetooth SpeakersPete-Ourn:uuid:b20fa926-ea74-6d41-f0bf-cb34757a26362018-01-08T16:58:08-07:00<p>Lol yeah, i suppose.</p>
Calif on Tube Amps in the Age of Bluetooth SpeakersCalifurn:uuid:b2519b4a-9243-5ad5-a849-49dcfe5782d42018-01-08T16:11:28-07:00<p>JFETs with pilot lights.</p>
Pete-O on Tube Amps in the Age of Bluetooth SpeakersPete-Ourn:uuid:46b2b3fd-a387-4632-d8e2-a6cd435cfead2018-01-08T11:43:32-07:00<p>Depends on your definition of "good". Tube amps tend to be less linear that solid state and add some even harmonics to the signal, giving them a very particular sound. They can be made more linear (hence ultra-linear pentode configs, but even these aren't perfect), but it's more effort to make them so. There are much better technologies that convey truer sonic reproduction. But I happen to love the sound of a tube amp. So... better? It's in the ear of the beholder.</p>
Jakezilla on Tube Amps in the Age of Bluetooth SpeakersJakezillaurn:uuid:3150eaf0-8dda-f717-ef22-d04384c90f1a2018-01-08T11:34:49-07:00<p>Great write up! Do you think a non-tube amp can sound as good as this? Maybe that is a good challenge for you...</p>
Pete-O on Tube Amps in the Age of Bluetooth SpeakersPete-Ourn:uuid:2a0f5f7d-0041-758f-8776-fd07de5aa8462018-01-08T10:05:28-07:00<p>Yep, you're exactly right. The "T" is for "Tension". It's difficult to determine where to draw the line on explanations for home page posts, so I made some things somewhat self evident. If it had been a tutorial proper, I would have expanded.</p>
Sembazuru on Tube Amps in the Age of Bluetooth SpeakersSembazuruurn:uuid:ff440fbb-fafd-ec15-fcec-ab46998476cd2018-01-08T09:52:49-07:00<p>Nice write-up. But I'm a bit confused with "LT" and "HT"... Is the "T" there "Tension" as in a nostalgic term for "Voltage"? Your younger readers might not figure this out if you don't define your terms...</p>