Useful Links https://www.agilent.com/http://www.acoustikmusik.com/https://ampbooks.com/mobile/amplifier-calculators/https://www.ankaudiokits.com/https://www.antiquetelephones.co.uk/https://www.tube-electronics.co.uk/https://www.aes.org/https://www.armstrong-audio.com/https://au.element14.com/capacitor-types-and-performancehttps://www.audiojumble.co.ukhttp://www.audiomaintenance.com/https://www.audionote.co.uk/https://www.audioaficionado.orghttps://www.audiokarma.orghttps://audiolounge.co.uk/https://www.audiomatica.com/wp/https://www.audiosciencereview.comhttps://www.avalondesign.com/https://www.bourns.com/http://brenelltape.co.uk.websitebuilder.prositehosting.co.uk/https://brixtonhillstudios.com/https://busoaudio.com/https://www.bvws.org.uk/https://www.caig.com/https://carnhill.co.uk/https://www.charcroft.com/distribution/http://charneyaudio.com/https://www.chord.co.uk/https://www.cinemag.biz/https://www.cine-real.com/http://www.claritycap.co.uk/https://www.collinsaudio.com/https://www.cpc.farnell.com/https://cpc.farnell.com/c/tools-maintenance/soldering/https://www.cricklewoodelectronics.com/http://www.customtubeconsoles.com/https://www.dadaelectronics.eu/uploadshttps://www.digikey.co.uk/en/resources/https://www.dranetz.com/http://www.drefahlaudio.com/mic/1_psu.htmlhttps://www.dripelectronics.com/https://diyaudioprojects.com/https://www.dwfearn.com/https://ekadek.com/https://www.electronics-notes.com/articles/basic_concepts/capacitancehttps://www.electrorent.com/https://www.elma.com/en/products/rotary-switcheshttps://www.eurotubes.com/https://www.fidelity-magazine.com/https://www.fluke.com/https://www.funky-junk.com/ https://www.gardinerhoulgate.co.uk/departments/6/Guitarshttps://www.gearspace.com/https://www.groupdiy.com/https://groupdiy.com/threads/barry-porter-net-eq.33256https://www.guitar-auctions.co.uk/https://www.guitar-classics.co.uk/https://www.guitarmaking.co.uk/https://www.haufe-uebertrager.de/https://www.hificollective.co.uk/https://www.hifishark.com/https://www.theiet.org/https://www.jensen-transformers.com/https://www.jukeboxmanuals.com/http://www.kraessemaschine.de/https://www.kewtechcorp.com/https://www.knipex.com/products/electronicshttps://www.cef.co.uk/catalogue/products/search?q=knipexhttps://linearaudio.nl/cyril-batemans-capacitor-sound-articleshttps://www.littelfuse.com/https://www.locomotiveaudio.com/https://www.lowtherloudspeakers.com/https://www.lundahltransformers.com/https://www.manley.com/https://www.me-geithain.de/en/https:/www.uk.megger.com/https://www.michellaudio.com/http://www.mikesfilmsound.com/https://www.mixonline.com/https://www.modularperfection.com/https://www.monodyn.com/https://www.motherload.co.uk/https://mullard.org/blogs/https://www.mundorf.com/audio/en/shop/Capacitors/https://www.musicalfidelity.com/https://www.nagraaudio.com/https://nagravox.com/https://www.nutsvolts.com/https://www.officialtranscriptors.com/https://www.one-electron.com/https://www.orbitsound.com/en-gbhttps://www.ortofon.com/hifi/products/accessories/https://www.cw-industrialgroup.com/About/Penny-Gileshttps://parts.wilsonaudio.com/parts/https://parttimeaudiophile.com/https://www.pbswisstools.com/https://www.peakelec.co.uk/https://www.peli.com/https://www.petervis.com/avo-meters/http://www.phaedrus-audio.com/https://postfade.co.uk/https://www.primaluna-usa.com/https://professordanaudio.com/https://www.quora.com/https://www.rammeter.com/https://www.rsgb.org/https://realgearonline.com/https://www.retrotone.co.uk/https://www.uk.rs-online.com/web/https://www.reverb.com/https://www.rupertneve.com/http://www.saturnsound.com/https://www.service-data.com/https://solen.ca/http://www.solid-tube-audio.de/https://soundgas.com/https://www.soundonsound.com/https://www.sowter.co.uk/https://www.srs-products.co.uk/https://www.stewmac.com/http://surreyelectronics.com/https://www.tapeheads.net/teachingmachines.co.ukhttp://www.techlabltd.co.uk/https://www.technotransformers.co.uk/https://testequipment.center/Product_Documents/https://www.thegearpage.net/https://www.thermionicculture.com/https://www.thiersch-mic.de/en/estm_geschichte.htmlhttps://www.tonepublications.com/http://www.totalaudiocontrol.com/https://www.tubeampdoctor.com/http://tubebooks.org/https://www.tubesandmore.com/http://www.tube-tech.com/http://www.valveradio.net/https://www.valveradio.co.uk/http://www.valvewizard.co.uk/http://velleman.co.uk/http://www.vintageaudioportal.com/https://vintageking.com/https://www.vintage-radio.net/forum/http://www.vintech-audio.com/https://www.voxac100.org.uk/woden.htmhttps://www.watfordvalves.com/http://www.watkinsguitars.co.uk/https://www.weller-tools.com/professional/http://wem-owners.com/https://whammerdyne.com/https://www.wima.de/en/https://worldradiohistory.com/Wireless_World_Magazine.htmhttps://www.vishay.com/https://www.voxac100.org.uk/woden.htmhttp://www.xelectrical.com/https://zaehl.com/