{"id":13534,"date":"2026-08-02T14:53:58","date_gmt":"2026-08-02T13:53:58","guid":{"rendered":"https:\/\/www.bartola.co.uk\/valves\/?p=13534"},"modified":"2026-08-02T14:53:58","modified_gmt":"2026-08-02T13:53:58","slug":"dht-lcr-riaa-preamp-by-salvatore-aragona","status":"publish","type":"post","link":"https:\/\/www.bartola.co.uk\/valves\/2026\/08\/02\/dht-lcr-riaa-preamp-by-salvatore-aragona\/","title":{"rendered":"DHT LCR RIAA preamp by Salvatore Aragona"},"content":{"rendered":"\n
<\/blockquote>\n\n\n\n

Here’s a very interesting project worth sharing to all, hopefully will inspire some of you on the same journey. Achieving a quiet and good sounding LCR phono stage is not a simple project:<\/p>\n\n\n\n

\n

Hi, <\/p>\n\n\n\n

I wanted to share with you the satisfaction of completing the most challenging project I\u2019ve tackled so far, and I wanted to thank you and Rod Coleman for the fantastic PCBs you provided. It is a phono stage built entirely around DHT triodes and SITs, featuring LCR RIAA equalization. Here are the key details: 1) First stage: two 3A5 sections in parallel with a UTC A-30 anode choke and 0.15\u00b5F Miflex KPCU capacitor; filament bias using a Pathaudio resistor; 45V anode, 2.2mA. 2) Second stage: 2SK79 SIT with a Tamura A8713 interstage transformer and SiC diode + resistor bias; 58V, 5.8mA. 3) LCR RIAA network with Noguchi Finemet-core inductors, Teflon capacitors, and Charcroft Z-Foil resistors. 4) Noguchi 600:50k Finemet-core transformer. 5) 01A tube with mu-output gyrator, direct-coupled (capacitor-less) to a MOSFET source follower PCB regulated at 15mA; 0.33\u00b5F Miflex KPCU output capacitor. 6) Four power supplies, each with an independent transformer, diodes, and CRC filter. 7) Anode power supply with a Telefunken mesh-plate vacuum rectifier and cLCLC filter; the first capacitor is 2.39\u00b5F, composed of a 2\u00b5F military-grade 800V polystyrene unit (actually two 4\u00b5F\/400V units in series) plus a 0.39\u00b5F Audio Note copper-foil PIO capacitor; Tango TC160-35 choke; other capacitors include polypropylene types and Tentlabs MEC50s. 8) The anodes of the 3A5 and 2SK79 are fed by Linear Audio T-Reg V5 series regulators. I\u2019m posting a few photos here; I\u2019d be happy if you published them on your site (feel free to decide whether or not to do so).<\/p>\n\n\n\n

The system is extremely quiet and, in terms of sound quality, far superior across all parameters to the Audio Note M5 Signature I previously owned.
Best regards
Salvatore Aragona<\/p>\n<\/blockquote>\n\n\n\n

\"\"<\/a>
LCR by Salvatore Aragona<\/figcaption><\/figure>\n\n\n\n
\"\"<\/a><\/figure>\n\n\n\n
\"\"<\/a><\/figure>\n\n\n\n
\"\"<\/a><\/figure>\n\n\n\n

Credits<\/h2>\n\n\n\n

Salvatore wished to mention the following people who inspired him and helped to realise this project: Rod Coleman, Antonio Maggio, and Giovanni Giorgianni and myself \ud83d\ude42 <\/p>\n\n\n\n

Excellent job Salvatore.<\/p>\n","protected":false},"excerpt":{"rendered":"

Here’s a very interesting project worth sharing to all, hopefully will inspire some of you on the same journey. Achieving a quiet and good sounding LCR phono stage is not a simple project: Hi, I wanted to share with you the satisfaction of completing the most challenging project I\u2019ve tackled so far, and I wanted … Continue reading “DHT LCR RIAA preamp by Salvatore Aragona”<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":13535,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_feature_clip_id":0,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2},"jetpack_post_was_ever_published":false},"categories":[911,449,448],"tags":[10,303,6,186,44,875,652,559,789,511,78,1469,1061],"class_list":["post-13534","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-gyrator-pcb","category-riaa","category-riaa-stages","tag-01a","tag-3a5","tag-dht","tag-dht-preamp","tag-gyrator","tag-gyrator-pcb","tag-hybrid-mu-follower","tag-lcr","tag-riaa","tag-riaa-phono","tag-rod-coleman-regulator","tag-sit","tag-source-follower"],"jetpack_publicize_connections":[],"jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p2r2tK-3wi","jetpack_likes_enabled":true,"jetpack-related-posts":[],"jetpack_featured_media_url":"https:\/\/i0.wp.com\/www.bartola.co.uk\/valves\/wp-content\/uploads\/2026\/08\/LCR-by-Salvatore-Aragona.png?fit=1542%2C1007&ssl=1","_links":{"self":[{"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/posts\/13534","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/comments?post=13534"}],"version-history":[{"count":1,"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/posts\/13534\/revisions"}],"predecessor-version":[{"id":13539,"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/posts\/13534\/revisions\/13539"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/media\/13535"}],"wp:attachment":[{"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/media?parent=13534"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/categories?post=13534"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/tags?post=13534"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}