Hello,
I am slowly gathering parts for my first build: the Tubelabs SSE. The board has many options and flexibility and I intend to use it. General outline below:
• B+ voltage of 450V (use as many different types of tubes as possible)
• 8 Ohm speakers
• Triode / UL switch
• Cathode feedback switch
• Rectifier switch
• Volume pot
• Switchable cathode bias resistors (680 Ohm, switching 680-750-910-
1K2-1K5-3K3 parallel with that)
• Considering a measurement point for tube current
Parts mainly as supplied in the parts list on the Tubelabs website, with addition of:
• C-14X choke
• Auxillary power supply cap
• Auricaps for C11 / C21
• CL1440 inrush limiter
• 2x 1N4007
For the power transformer I’m thinking of Edcor XPWR059 and output transformers Edcor CXSE25-8-5. Unfortunately, on my side of the pond (Europe, GER/NL/NOR) these things cost an arm and a leg. Any suggestions on:
• More affordable transformers
• Toroidal or “conventional” ?
And obviously, any pointers on making this plan a success are utmost welcome😀!
Cheers, Bill
I am slowly gathering parts for my first build: the Tubelabs SSE. The board has many options and flexibility and I intend to use it. General outline below:
• B+ voltage of 450V (use as many different types of tubes as possible)
• 8 Ohm speakers
• Triode / UL switch
• Cathode feedback switch
• Rectifier switch
• Volume pot
• Switchable cathode bias resistors (680 Ohm, switching 680-750-910-
1K2-1K5-3K3 parallel with that)
• Considering a measurement point for tube current
Parts mainly as supplied in the parts list on the Tubelabs website, with addition of:
• C-14X choke
• Auxillary power supply cap
• Auricaps for C11 / C21
• CL1440 inrush limiter
• 2x 1N4007
For the power transformer I’m thinking of Edcor XPWR059 and output transformers Edcor CXSE25-8-5. Unfortunately, on my side of the pond (Europe, GER/NL/NOR) these things cost an arm and a leg. Any suggestions on:
• More affordable transformers
• Toroidal or “conventional” ?
And obviously, any pointers on making this plan a success are utmost welcome😀!
Cheers, Bill
I bought Hammond 374bx and Edcore GXSE15-5-8 and Hammond 159q from don-audio, about half of the price compared to your list.
Do you really need cathod bias resistor above 1K? Look at the application table on tubelab, I ordered 330 to 820. Initially planed on using a switch, then realised that after initial setup are changing resistor equals changing tube, skipped the switch and used a screw connector for the resistors. Still changeable but not by a switch.
Do you really need cathod bias resistor above 1K? Look at the application table on tubelab, I ordered 330 to 820. Initially planed on using a switch, then realised that after initial setup are changing resistor equals changing tube, skipped the switch and used a screw connector for the resistors. Still changeable but not by a switch.
Hi Bill, great timing. I'm about to fire up my SSE as well.
Using a local mains transformer with dual secondary's - 275 and 300v. The board is wired in Triode and toggle switches for the cathode bias.
When I get it working, will wire the Triode /UL and SS/Valve rectifier switches.
The OPTs are Edcor CXSE25 and the PS has a 7H/220ma choke. I'm thinking of going with a 6P3S and 5U4g as the first tubes to test 🙂
Good luck with your build.
Using a local mains transformer with dual secondary's - 275 and 300v. The board is wired in Triode and toggle switches for the cathode bias.
When I get it working, will wire the Triode /UL and SS/Valve rectifier switches.
The OPTs are Edcor CXSE25 and the PS has a 7H/220ma choke. I'm thinking of going with a 6P3S and 5U4g as the first tubes to test 🙂
Good luck with your build.
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Hi,
Thanks for your input! After tough negotiations I can put the SSE in the living quarters if the speakers are not too big so the Edcor GXSE15-5-8 could make sense and saves some budget to buy some nice drivers 😉.
After more reading I think I'd like to avoid the big Edcor and likes as the massive amount of iron may also cause some distortion. I've made an enquiry at a local company for an one electron ubt-2 clone with UL tap, see what they can do.
Also still considering toroids: this one looks like a nice fit: https://sklep.toroidy.pl/en_US/p/TTG-EL84SE-Tube-output-UL-transformer-5kOhm-EL84-6V6-SE/572 but can't find experiences with that in SSE or a comparison between toroid and EI core OPT's.
I'm aiming for a B+ of 450 V so I can use EL34, 6L6GC and KT88. Using a fixed resistor of 680 ohm and 680-3K3 in parallel with that results in an actual cathode resistance of 340-564 ohm, which seems to fit the simulations on Tubelab. Using a switch because I like options and exchanging tubes is then not equal to taking the amp apart.
Looks nice. Any sound already?
I received the parts today and soldered the first resistors. Hopefully after the weekend more progress.
Cheers, Bill
Thanks for your input! After tough negotiations I can put the SSE in the living quarters if the speakers are not too big so the Edcor GXSE15-5-8 could make sense and saves some budget to buy some nice drivers 😉.
After more reading I think I'd like to avoid the big Edcor and likes as the massive amount of iron may also cause some distortion. I've made an enquiry at a local company for an one electron ubt-2 clone with UL tap, see what they can do.
Also still considering toroids: this one looks like a nice fit: https://sklep.toroidy.pl/en_US/p/TTG-EL84SE-Tube-output-UL-transformer-5kOhm-EL84-6V6-SE/572 but can't find experiences with that in SSE or a comparison between toroid and EI core OPT's.
I'm aiming for a B+ of 450 V so I can use EL34, 6L6GC and KT88. Using a fixed resistor of 680 ohm and 680-3K3 in parallel with that results in an actual cathode resistance of 340-564 ohm, which seems to fit the simulations on Tubelab. Using a switch because I like options and exchanging tubes is then not equal to taking the amp apart.
Looks nice. Any sound already?
I received the parts today and soldered the first resistors. Hopefully after the weekend more progress.
Cheers, Bill