Hmm very clean build, worked on first go... from now on you show how they make an Itch, Fran and Salas you made to Itchers emeritus.😀😀😀
It's silent like a tomb, Valve Itch have a very good characteristic: pops & cracks noise coming from vinyl sounds low level.
Keep clean notes, now you said dead silent, newer to tubes phono people will be asking, Merin, how you grounded this and how you connected that. Photos from underside they will ask also.
I followed Fran's grounding, star ground, ground wire coming from PSU not direct to star ground: between them I use the ground loop breaker. I learned doing other valve phono preamps it's very important twisted wires & for heater & B+ wires don't cross or be near between them, heater wires also must be always near chassis so chassis acts like a shield avoiding noise in the heaters. Heaters regs I used PRP resistors, BG NP & Panasonic FM. Only boutique parts are used in the phono:
Resistor 22K B+ between 6SN7 & 6N2P-EV (Mills+Shinkoh)
Load cartridge resistor 47K (Audionote tantalum)
Resistor R3 47R Takman carbon
Rest of resistor are common cheap carbon
Heater elevator cap 1uf 450V Auricap
Output caps 3.3uF 450V Auricap
Step-up resistor Shinkoh
Ground loop breaker used
Attached pic, enjoy.
Resistor 22K B+ between 6SN7 & 6N2P-EV (Mills+Shinkoh)
Load cartridge resistor 47K (Audionote tantalum)
Resistor R3 47R Takman carbon
Rest of resistor are common cheap carbon
Heater elevator cap 1uf 450V Auricap
Output caps 3.3uF 450V Auricap
Step-up resistor Shinkoh
Ground loop breaker used
An externally hosted image should be here but it was not working when we last tested it.
Attached pic, enjoy.
Attachments
Is the orange/red/brown/black you use from reg to phono good for HV, or is it some general purpose signal cable?
Splendid... ultra clean build... nice soldering works...
Interestingly I learned a lot from esp gnd loop breaker you use.... Where exactly do you connect arm earth wire in the schematic you posted ?
Interestingly I learned a lot from esp gnd loop breaker you use.... Where exactly do you connect arm earth wire in the schematic you posted ?
The subchassis is a sandwich aluminium, mumetal/permalloy, stillpoints, connected to star ground.
Arrh !
You make 26 as well Felipe !
I looked at this also...
...good with attenuator between Itch & 26 maybe.
Felipe...You told me a year ago...but I forget...
...You are using 'balanced amps'...yes ?
..I think you built yourself Nelson something ( F? ).
What line-stage do you use/build ?
This is what you listen to 'Itch' with now...before amps/s ?
Si.
Hope that makes sense.
( nice grommets !!! )
You make 26 as well Felipe !
I looked at this also...
...good with attenuator between Itch & 26 maybe.
Felipe...You told me a year ago...but I forget...
...You are using 'balanced amps'...yes ?
..I think you built yourself Nelson something ( F? ).
What line-stage do you use/build ?
This is what you listen to 'Itch' with now...before amps/s ?
Si.
Hope that makes sense.
( nice grommets !!! )
Nice... so TT GND is connected only to preamp chassis and NOT to circuit gnd.
The chassis itself connects to the circuit MINUS only throu the GND loop breaker circuit.... 🙂
TT gnd it's only connected to chassis, the gnd coming from separate PSU goes to the ground loop breaker so you have a clean ground star without any ground loop where to connect all grounds, see attached pic.
Attachments
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