It seems like there is few new DV 336SE owners so I decide to go over few small details in regards to this amp,hopefully this will save you some time and money down the road ,this is base on my own opinion and result of multiple testings
-DV 336SE won't benefit much from modding but if you "must" then I would recommend simple Fitz mod (hum)
-Best thing you can do and see biggest improvement is running dedicated DAC (not DAC/amp ) via decent RCA cables
This is crucial and will get rid of all the distortion /interference and hum-some tubes need burn in time
Note:
if you have no other choice but have it connected to DAC/amp and want to get rid of that interference-distortion,etc then getting rid of power ground it should help in a big way but I wouldn't recommend it for obvious reason
Tubes (based on my own preference/natural sounding )-rule of thumb, I use my DAC as reference point ;
Power tube -not as important as the driver (little guy) some would say but I never found pear shaped tube that would set the stage for SS sound , for me Good 7236 is the way to go ,this tubes are very dynamic with full and well controlled low end but they are notorious for loose particles (solder) and slightly grainy highs since most you can find are used and abused,I bought crap load of Cetron and TS 7236 back in the days and could only keep one of each ,I wouldn't touch white label 7236 with 6 foot pole
If you prefer more laid-back with drop of syrup on top sound then the best sounding one I have tested and previously my go to tube on BH Crack was GEC Hammersmith 5998 (hard to find) or TS 5998,I never had any luck with Chatham 5998 and never tested famous WE 421A
Driver tube -make or brake kinda deal
it's all here ,this thread is like national treasure in case someone missed it
https://www.head-fi.org/threads/the-reference-6sn7-thread.117677/
Upgrading my daily SS set up give me good opportunity to play with DV336 SE again the end results was very surprising ,my tube amp sounds Very close to Audio-gd R2R11/LCD-2.2 ,I'm very happy camper
and this is very budget friendly
Chain;
PC=>USB Hub (good interference dumpers)=>cheap audio USB cable (2x ferrite chokes)=> old Schiit Modi 24/96 (USB powered )=>RAMM Audio S600 RCA cables=> main event DV 336SE=>HD 650
Tubes used ;
Power -TS 421A (NOS $ 90.00)-more air ,low end is almost the same as 7236 but mids slightly up front , no grain extended highs
Driver-Arcturus 6SN7GT ( $6.00) got lucky with this one ,similar sound to 6SN7W but slightly better separation
Other drivers tested
Cheers
Edit ;Topping D50 have my name on it so I will be swapping Modi soon since it doesn't support DSD