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6L6gc Clementine

PostPosted: Mon May 26, 2014 7:31 am
by noisy
Hi, I've just finished another Clementine,with 6L6gc's I had.I used an old 360-0-360v power transformer from an old PA .A 5H choke was used .It sounds really good but lacks bass.I used 5k OPT'S and did the standard build on the circuit board, with 1.5k R18.R19 resistors.I measured the B+ at 414v and pin 4 at 404v.Pin 8 has 35.6v. All the readings are with valves in. Can anyone help with the lack of bass .

Re: 6L6gc Clementine

PostPosted: Mon May 26, 2014 8:33 am
by TomMcNally
What kind of output transformers ?

Re: 6L6gc Clementine

PostPosted: Mon May 26, 2014 6:17 pm
by noisy
I used 5k units from VT4C website,i cant find the number but they're good for 25w.I used them on another amp and they work good.

Re: 6L6gc Clementine

PostPosted: Tue May 27, 2014 7:24 am
by noisy
noisy wrote:I used 5k units from VT4C website,i cant find the number but they're good for 25w.I used them on another amp and they work good.

I plugged EL34's in to see what happens and got some more bass, but not earth shattering.

Re: 6L6gc Clementine

PostPosted: Tue May 27, 2014 8:02 am
by TomMcNally
What's your source material? Do you have a preamp with Bass Boost (Loudness) or anything?
Earth Shattering bass isn't *created* by the amplifier, it's passed through from the input material.

The Chubby Clementine I built Saturday has plenty of bass, using either my Adcom preamp or
the Parks Audio Budgie with Bass Boost on.

Re: 6L6gc Clementine

PostPosted: Tue May 27, 2014 6:08 pm
by noisy
I use a YAQIN phono stage with two EI 12ax7 and a turntable for records, or a NAD cd player direct into amp. These have no adjustments or bass boost and they give plenty of bass on the other clementine I made. I dont use a sub anymore with the metronome speakers.I'll keep swapping valves to find more bass.

Re: 6L6gc Clementine

PostPosted: Tue May 27, 2014 11:04 pm
by noisy
I got the bass back!!!!!!! I swapped the RCA 6sl7 [vt229] with a RAYTHEON 5691 from another amp and have tons of bass. Now I am looking for another 5691 as there is so much difference.I'll post a picture if can make the file size smaller

Re: 6L6gc Clementine

PostPosted: Wed May 28, 2014 7:34 am
by EWBrown
Sounds like you had a bad 6SL7 (or perhaps a mis-marked 6SN7). [:)

Re: 6L6gc Clementine

PostPosted: Wed May 28, 2014 5:30 pm
by noisy
I had a pair of RCA JAN VT229 and both did this ......just my luck! I have a GE 5691 on the way.

Re: 6L6gc Clementine

PostPosted: Sun Dec 14, 2014 5:37 am
by noisy
Hi All,
I revisited the amp,and changed the output trans to BEZ 4K ...........cheap but good.Now I have much more bass.I put VALVE ART 350B's in and they're good, warm and musical.I found an ADZAM 6SL7 and it's bought the amp to life, heaps of bass and clarity.Now to attack the KT88 version I made.

Re: 6L6gc Clementine

PostPosted: Sun Dec 14, 2014 8:08 am
by Shannon Parks
Love the huge Bakelite knob and distressed wood chassis.

Shannon

Re: 6L6gc Clementine

PostPosted: Wed Jan 28, 2015 5:40 am
by noisy
Hi,
I just got some NOS GEC KT66 at a nice price. Wow ....what a difference, so much bass and creamy mids.

Re: 6L6gc Clementine

PostPosted: Wed Jan 28, 2015 8:51 am
by EWBrown
Has anyone tried 2C52s , these are 12 volt filament dual triodes similar to 12SL7, with the same "8BD" pinout, but with somewhat more gain, closer to that of a 12AX7.
Of course, these would be restricted to 12V filament Clementines, using 1626 or 12V6GT. I recently scored ten of these 2C52s, at a really good price [:)

/ed B

Re: 6L6gc Clementine

PostPosted: Wed Jan 28, 2015 12:20 pm
by Shannon Parks
EWBrown wrote:Has anyone tried 2C52s , these are 12 volt filament dual triodes similar to 12SL7, with the same "8BD" pinout, but with somewhat more gain, closer to that of a 12AX7.


I've bought a few for my Darling Clementine, and Thermion uses them in his 1625 Clementine (also 12.6V filaments). Very nice tubes! If you ever can pick them up for a reasonable price, they're worth it.

Shannon