Jolly_Rancher
New member
HELLO FRIENDS AND NEIGHBORS,
So, it turns out that my Dual Recto actually came with a quad of vintage Tesla EL34's from the last production of the Czech factory. Way cool.
But I went further and ordered a handful of new tubes from Doug's (great vendor, excellent shipping practices, btw)... 3 new Tung-sol reissues, a Sovtek LPS matched and balanced, and a Ruby 12AX7AC7 HG+ matched and balanced. (the matched and balanced spec is for the phase inverter spot, but works anywhere). Also got some NOS JAN Philips 5U4GB rectifiers (anyone know about these? looks like they were made in 1985? Far from the golden age of tube manufacturing, but USA made, nonetheless), and a matched quad of mesa green STR 440 (6L6).
I will add my thoughts to this post later, as I try them out. I bought enough to re-tube the whole Dual Recto, but I think my Tweaker 15 will be a better platform for hearing the subtleties of each preamp tube based on that amp's simple design.
EDIT: (what I heard when using each of these 12AX7's in V1 of my Egnater Tweaker 15 head w/ Mercury OT)
-Tung-Sol reissue: the first thing I noticed were the crystalline highs that this tube imparts on the signal. but this doesn't mean it sounds thin. The gain is pretty high compared to the matched and balanced Ruby AC7 HG+. The Tung-Sol reissue has a wide, huge sound, like it's scooped in the mids.
-Ruby AC7 HG+: Quieter than the other tubes, has a great balance of frequencies, sounds great under higher gain, tight.
-Sovtek LPS: Punchy and louder than the AC7 HG+! This tube, when I hit the bright switch on my amp had a harsh high end. Under higher gain, it has a harsh quality. The gain structure is good, unlike the Mullard reissue.
-Mullard reissue (just to compare): LOUD, noticeably louder as V1 than the AC7 HG+. A dark sounding tube with punchiness. When distorted sounds almost fuzzy/flabby. Not my favorite high-gain sound.
-Mesa STR 440 6L6: I installed the 5U4GB's and STR 440's in the 1993 Dual Recto. I like the squashed sound of tube rectifiers, but that's because my name's not Ola. The STR 440's sounded quieter or "smaller" than the Tesla EL34's. Much different than the Tesla's. The EL34s have that awesome, full mid range spectrum, while the the STR 440's were missing all that. I guess I want to say they sound worse, but I want to save the Tesla's. I'm not sure worse is the right description, as I think the clean channel sounds better with the STR 440's, and possibly even the high-gain side too after a few knob tweaks, but initially as the knobs were set for the EL34's, I was missing some of those mids until I changed a few things.
So, it turns out that my Dual Recto actually came with a quad of vintage Tesla EL34's from the last production of the Czech factory. Way cool.
But I went further and ordered a handful of new tubes from Doug's (great vendor, excellent shipping practices, btw)... 3 new Tung-sol reissues, a Sovtek LPS matched and balanced, and a Ruby 12AX7AC7 HG+ matched and balanced. (the matched and balanced spec is for the phase inverter spot, but works anywhere). Also got some NOS JAN Philips 5U4GB rectifiers (anyone know about these? looks like they were made in 1985? Far from the golden age of tube manufacturing, but USA made, nonetheless), and a matched quad of mesa green STR 440 (6L6).
I will add my thoughts to this post later, as I try them out. I bought enough to re-tube the whole Dual Recto, but I think my Tweaker 15 will be a better platform for hearing the subtleties of each preamp tube based on that amp's simple design.
EDIT: (what I heard when using each of these 12AX7's in V1 of my Egnater Tweaker 15 head w/ Mercury OT)
-Tung-Sol reissue: the first thing I noticed were the crystalline highs that this tube imparts on the signal. but this doesn't mean it sounds thin. The gain is pretty high compared to the matched and balanced Ruby AC7 HG+. The Tung-Sol reissue has a wide, huge sound, like it's scooped in the mids.
-Ruby AC7 HG+: Quieter than the other tubes, has a great balance of frequencies, sounds great under higher gain, tight.
-Sovtek LPS: Punchy and louder than the AC7 HG+! This tube, when I hit the bright switch on my amp had a harsh high end. Under higher gain, it has a harsh quality. The gain structure is good, unlike the Mullard reissue.
-Mullard reissue (just to compare): LOUD, noticeably louder as V1 than the AC7 HG+. A dark sounding tube with punchiness. When distorted sounds almost fuzzy/flabby. Not my favorite high-gain sound.
-Mesa STR 440 6L6: I installed the 5U4GB's and STR 440's in the 1993 Dual Recto. I like the squashed sound of tube rectifiers, but that's because my name's not Ola. The STR 440's sounded quieter or "smaller" than the Tesla EL34's. Much different than the Tesla's. The EL34s have that awesome, full mid range spectrum, while the the STR 440's were missing all that. I guess I want to say they sound worse, but I want to save the Tesla's. I'm not sure worse is the right description, as I think the clean channel sounds better with the STR 440's, and possibly even the high-gain side too after a few knob tweaks, but initially as the knobs were set for the EL34's, I was missing some of those mids until I changed a few things.
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