Page 1 of 1

Clementine vs. GSG (or ST35)

PostPosted: Fri Dec 05, 2014 12:45 am
by ekubota
I'm thinking about building a point-to-point Clementine or GSG to use with my Budgie line stage (I'm currently using the line stage with the power section of an '80s NAD integrated amp).

A few initial questions are below. My sources are digital and vinyl. I listen in a small apartment at moderate volumes through Pioneer BS21 speakers (which seem to have a fairly low sensitivity of 84dB) and Stax headphones (not sure of the sensitivity, but I doubt they need much power; the perceived volume at a given output level seems higher than with the Pioneer speakers). I listen to a lot of classic rock and jazz, with some classical, and my tastes in audio equipment are probably closer to the "precise" end of the spectrum; transparency and imaging are important, and I like to hear the quality of the source, rather than coloration induced by my system. Thanks in advance!

1. Given my system, which amp do you think is preferable? Would either be suitable?
1a. If the Clementine is suitable, which version would be best? I believe the Ultra version has lower gain and more power, so I thought it might be better. Again, I am using a Budgie line stage, so hopefully that combination would work well.
2. What are the general subjective tonal characteristics of the Clementine and GSG? And how different are the input sensitivity, power, THD, etc.? My impression from searching this forum is that the Clementine 6L6 and Ultra both have somewhat similar characteristics to the GSG, but I'm not sure this is right.
3. Would a DIY ST35 be overkill for my system? I was thinking about ordering the Triode kit without chassis (I want to use an oak and aluminum chassis to match my Budgie line stage), or perhaps making a PTP version with Edcor transformers. I like the idea of lower-cost, readily available new production tubes, but I'm not sure I need that much power and I like the simplicity of the other designs.

Re: Clementine vs. GSG (or ST35)

PostPosted: Fri Dec 05, 2014 9:00 am
by SteveH
Well considering how inefficient those speakers are - I would say the more power you can get; the better. For classic rock I'd say you'd need an ST70. Its not so much about volume, but assuring you have the power you need for the bass riffs, etc.

Re: Clementine vs. GSG (or ST35)

PostPosted: Sat Dec 06, 2014 1:42 pm
by ekubota
Thanks, but any thoughts as between the Clementines and GSG? I just checked and my normal listening levels are around 80dB; I really don't think I need an ST70.

Re: Clementine vs. GSG (or ST35)

PostPosted: Thu Dec 11, 2014 9:02 pm
by ekubota
Update: I upgraded to speakers with 89dB sensitivity. A few questions about the Clementine 6L6 Ultra:

1. Is the Edcor GXSE15-8-5K output transformer already set up with ultralinear taps? Do I need to make any special requests to Edcor, or is this model already appropriate for a Clementine 6L6 Ultra?

2. I had some questions about the power transformer and related parts. For F1 should I get a fuse rated for 1.5A, 250V? Also, the connection chart says SW1's pin 3 should go to the "other side of the primary, as the neon bulb
is parallel to the primary winding." What does this mean? Can I just use a regular SPST toggle switch with two terminals and connect it between the CL-90 and one side of the primary?

3. Grounding: should I use a three-prong power cord with the ground pin connected to the chassis? Should I connect all the other grounds shown on the schematic to the black/red wire of the power transformer secondary?

4. Heaters: the schematic refers to "Heater A" and "Heater B," but also shows 6.3V L A and L B for the 6SL7 and a 6.3Va and b for each 6L6. How are these connections made? Should "Heater A" just go to 6.3V L A and each 6.3Va, while "Heater B" goes to 6.3V L B and each 6.3Vb?

5. Choke: is the Hammond 156R okay? http://www.mouser.com/Search/ProductDet ... ey546-156R

6. Finally, will a Budgie line stage have sufficient output voltage to drive the Ultra to full power?

Re: Clementine vs. GSG (or ST35)

PostPosted: Sun Dec 14, 2014 7:28 am
by Shannon Parks
ekubota wrote:1. Is the Edcor GXSE15-8-5K output transformer already set up with ultralinear taps? Do I need to make any special requests to Edcor, or is this model already appropriate for a Clementine 6L6 Ultra?


UL taps are standard.

ekubota wrote:2. I had some questions about the power transformer and related parts. For F1 should I get a fuse rated for 1.5A, 250V? Also, the connection chart says SW1's pin 3 should go to the "other side of the primary, as the neon bulb
is parallel to the primary winding." What does this mean? Can I just use a regular SPST toggle switch with two terminals and connect it between the CL-90 and one side of the primary?


Yes, you can use a SPST switch and omit the neon bulb switch. Correct - 1.5A fuse.

ekubota wrote:3. Grounding: should I use a three-prong power cord with the ground pin connected to the chassis? Should I connect all the other grounds shown on the schematic to the black/red wire of the power transformer secondary?


Use a star ground or buss bar or ground wire for the system ground that is separate from the chassis. As the end, connect it to the chassis with one wire.

ekubota wrote:4. Heaters: the schematic refers to "Heater A" and "Heater B," but also shows 6.3V L A and L B for the 6SL7 and a 6.3Va and b for each 6L6. How are these connections made? Should "Heater A" just go to 6.3V L A and each 6.3Va, while "Heater B" goes to 6.3V L B and each 6.3Vb?


You've discovered a label error on the schematic. Your assumption is correct.

ekubota wrote:5. Choke: is the Hammond 156R okay? http://www.mouser.com/Search/ProductDet ... ey546-156R


Yes.

ekubota wrote:6. Finally, will a Budgie line stage have sufficient output voltage to drive the Ultra to full power?


Yes.

Shannon

Re: Clementine vs. GSG (or ST35)

PostPosted: Sun Dec 14, 2014 9:59 pm
by ekubota
Thanks very much.

Use a star ground or buss bar or ground wire for the system ground that is separate from the chassis. As the end, connect it to the chassis with one wire.


And the green lead of the power cord (that goes to the ground pin) should be connected to the chassis at the same point, right?

Re: Clementine vs. GSG (or ST35)

PostPosted: Mon Dec 15, 2014 10:55 am
by Shannon Parks
ekubota wrote:Thanks very much.

Use a star ground or buss bar or ground wire for the system ground that is separate from the chassis. As the end, connect it to the chassis with one wire.


And the green lead of the power cord (that goes to the ground pin) should be connected to the chassis at the same point, right?


Technically, no. It should be nearby with its own dedicated screw and crimped ring connector.

Shannon

Re: Clementine vs. GSG (or ST35)

PostPosted: Thu Dec 25, 2014 3:31 pm
by ekubota
Thanks again. Any thoughts on using metal envelope 6L6 tubes? Other than connecting pin 1 to ground, do I need to make any other changes (different resistor values, etc.) to the stock 6L6 Ultra schematic? For reference, I would be switching between the metal 6L6s and JJ 6L6GCs.

Re: Clementine vs. GSG (or ST35)

PostPosted: Fri Dec 26, 2014 1:02 am
by battradio
Metal 6L6^'s run hot as hell it is normal , they are Rated 19 watts dissipation not the 23 or more of new 6L6GC's , metal 1614's are an improved metal 6L6