Sounds like your tubes have some heater-cathode leakage. The solution is to use a different tube.
Recent Images In This Thread
Related Forum Threads
- [Review] Ortofon HD-Q7 Last post on 1/16/11 at 11:59pm in Headphone Amps (full-size)
- All Aluminum Bottlehead Amp.... Last post on 11/10/12 at 5:17pm in Headphone Amps (full-size)
- Schiit Valhalla and the overly bright mids that are masking the bass Last post on 5/24/12 at 1:40pm in Headphone Amps (full-size)
- Do I even need a headphone amp (Tesla T1 / Yamaha home cinema amp) Last post on 11/30/13 at 7:52am in Headphone Amps (full-size)
- Just looked at the Bottlehead amps and... Last post on 8/1/14 at 11:14pm in Headphone Amps (full-size)
Head-Fi Buying Guide (Desktop Amps & DACs)
Last edited: 11/30/16
- Head-Fi Buying Guide (Desktop Amps & DACs) 2Last edited: 11/28/16
- Diy Beginners GuideLast edited: 7/22/13
- Headphone ImpedanceLast edited: 8/18/12
Intro The Meze 12 Classics has been provided to me by the Meze company as part of the official European review tour in exchange for my honest opinion. Later on Meze decided the participants can...
Hello and thanks for getting to my review! Firstly, need to tell you that this DAC/headamp has no battery inside, so those needing something to listen while jogging or walking might need to...
SPECS: Driver Type 8mm Dynamic Plug Type 3.5mm Gold-plated Cord Length 1.3m Y Frequency Response 12 Hz – 22...
1MORE Capsule Dual-Driver In-Ear Headphones Quick Review by mark2410 Thanks to 1MORE UK for the review sample. Full review...
Massdrop x Noble X Universal IEM Earphone Quick Review by mark2410 Thanks to Massdrop for the loaner. Full review...
Crack;Bottlehead OTL - Page 111post #1651 of 79773/21/13 at 10:25am
Head-Fi's Best Sellerspost #1652 of 79773/21/13 at 1:08pmQuote:
OK, will do! This humming noise comes and goes if you tap on the tube with a pencil and then comes back after a bit.
Is there a technical reason for what's happening like part of the guts that aren't supposed to be touching actually are, or something? The guy I bought the tube from claimed it tested 95/95 and had 'no microphonics.' Meanwhile if you tap it lightly with a pencil it sounds like a mule kicking a spring reverb in a guitar amp.post #1653 of 79773/21/13 at 1:19pmpost #1654 of 79773/21/13 at 1:21pmpost #1655 of 79773/21/13 at 2:07pm
I gave him the benefit of the doubt that the postman was playing football with the package on the way to my house.
The hum isn't all that loud (you quit hearing it as soon as you start playing music at low volume.) How risky is it to use leaking tubes though in terms of them going 'full short' ??post #1656 of 79773/21/13 at 2:12pm
As long as it isn't crackling or popping it will probably be OK. And sometimes the hum can reduce with some burn time. Sometimes not.post #1657 of 79773/21/13 at 2:29pm
This is a circa 1943 RCA 6AS7G. I noticed people online doing things like baking them in the oven to 'dry out' the bakelite base in case of shorting that way. I presume the heat generated while being used would cause that moisture to flee the base though. I'm going to test the 'bulb' from the base to make sure it's not loose tonight. I'd love for it to quiet down because I really like the way it sounds. I need to befriend someone locally with a tube tester and the knowledge required to use it.post #1658 of 79773/21/13 at 3:15pmQuote:Originally Posted by silverhead
This is a circa 1943 RCA 6AS7G. I noticed people online doing things like baking them in the oven to 'dry out' the bakelite base in case of shorting that way. I presume the heat generated while being used would cause that moisture to flee the base though. I'm going to test the 'bulb' from the base to make sure it's not loose tonight. I'd love for it to quiet down because I really like the way it sounds. I need to befriend someone locally with a tube tester and the knowledge required to use it.
Not sure what circa I have, but I've got no noise. I can post a pic tonight of it. In fact have three spares.post #1659 of 79773/21/13 at 3:51pm
How do the pins look on that tube silverhead? Back in mid-2011, I had an RCA12bh7 blackplate with an unfortunate hum issue, and Doc suggested buffing the pins with fine steel wool as a possible fix. I used fine grain sand paper, in the absence of steel wool, and then inserted and removed the tube a dozen or so times. The hum was completely eliminated.
I don't know if this has the same probability of success on a power tube, but I figured it would be worth tossing out there.post #1660 of 79773/21/13 at 10:25pm
I get after everything that comes to the house with Caig DeOxit D5 and Q-tips. I can try to burnish the tips, but they're already pretty clean and newish looking I have 00 steel wool to try though. My guess is that it took a hard knock on the USPS truck. I have more coming in the mail.
I've been trying to score oddball 12AU7 equivalents to see what sort of differences I hear as well. It's been fun.
Edited by silverhead - 3/21/13 at 10:28pmpost #1661 of 79773/21/13 at 10:49pmpost #1662 of 79773/21/13 at 11:13pmQuote:
Hard to say. I've been looking around for awhile and it seems they basically go for the price of the kit, if they are built well. Everything I've read on the bottlehead forums is pretty wary of buying prebuilt kits because if any issues show up down the road they are hard to pinpoint. If the kit isn't built well it could easily be a mess.
edit: Should also add you shouldn't sell the kit for more than it costs directly from bottlehead on the head-fi forums unless you are a member of the trade.
Edited by elwappo99 - 3/21/13 at 11:14pmpost #1663 of 79773/22/13 at 12:21ampost #1664 of 79773/22/13 at 4:07pm
it is a DIY kit, but bottlehead will assemble it for a fee im pretty sure. I was part of the first groupbuy i believe for the Crack amp . I don't really use the amp anymore but still deciding on whether I want to keep it or not, I have an emotional attachment too actually since I built it. I haven't been on head-fi for awhile, pursuing other hobbies. The only thing I cant seem to live without is IEMs though.post #1665 of 79773/22/13 at 4:37pm
We no longer build amps for customers. My techs are hired for R&D work and they don't have the time to fit kit assembly into their schedule any more. But anybody can build one of these kits. There are literally thousands of Bottlehead kits out there that have been built by beginners.
- Crack;Bottlehead OTL
Head-Fi's Best Sellers
- Head-Fi Buying Guide (Desktop Amps & DACs) 2
- › Stax SRM-Xh withoriginal wallplug 1 minute ago
- › Best IEMS under 300-350$? 3 minutes ago
- › Brand new and sealed Cayin I5 DAP and used 200gb Sandisk Micro SD card 4 minutes ago
- › Absolute best budget earbuds? 5 minutes ago
- › Cmoy amps still worth it? 5 minutes ago
- › Rockbox Xduoo X3 6 minutes ago
- › Hifiman he-400i Impressions and Discussion 6 minutes ago
- › The Official Sony MDR-Z1R Flagship Headphone Thread (Live From IFA... 7 minutes ago
- › Knowledge Zenith (KZ) impressions thread 7 minutes ago
- › Band Name Game II 8 minutes ago
- › Meze 12 Classics by OSiRiSsk
- › Roland Mobile UA UA-M10 USB Audio Interface by raoultrifan
- › Brainwavz M100 IEM Noise Isolating Earphones with Remote &... by NA Blur
- › 1MORE Capsule Dual Driver In-Ear Headphones with In-line Microphone... by mark2410
- › Massdrop x Noble X Universal IEM by mark2410
- › HIFIMAN HE1000 V2 Over Ear Planar Magnetic Headphone by MattTCG
- › Bluedio V (Victory) Pro Patented PPS12 Drivers Wireless Bluetooth... by mark2410
- › Effect Audio - Thor Silver II by Falconlistener
- › Edifier R2000DB Powered Bluetooth Bookshelf Speakers - Near-Field... by ryanjsoo
- › Yamaha MusicCast WX-010 Wireless Speaker (White) by mark2410
- › Head-Fi Buying Guide (Travel Headphones)
- › Head-Fi Buying Guide (CanJams)
- › FiiO X3II DAP firmwares with custom themes
- › Flawless Album Suggestions
- › The Audiophile Scene in a Third World Country...
- › Mad Lust Envy's Headphone Gaming Guide,...
- › Mad Lust Envy's Headphone Gaming Guide,...
- › Mad Lust Envy's Headphone Gaming Guide:...
- › Chord Mojo FAQ
- › Head-Fi Logo Gear