Vostok Bezel Mods

From NATO'ed to Bezel mods

Vostok Amphibia 110640 + Bandukh Bezel

Murphy 1050 bezel + Seiko 'Pepsi' insert
=

Vostok "mod" Amphibia 420432

Budget SE OPTs - Edcor and Noguchi

All output transformers were tested in the je2a3 amp using the same procedure as I did in the Hammond 125ESE many moons ago. Listening sessions were done through the same amp driving a single Altec 2-way speaker system. 

Edcor GXSE15-16-3.5K
Weight = 2.75 lbs

Primary Z = 3.5K

Secondary = fixed @ 16 ohm

Frequency Response = 40Hz - 18kHz, <1dBu 

Maximum DC current = 190 ma.

Core Material = M6, 29 ga. grain oriented steel

I ordered this Edcor OPT to get a feel on what's available to a cash-strapped US-based DIYer. It took over 3 weeks to be delivered to my doorstep at a total cost of $58.67. The nice square waves indicate quality manufacturing. Bass performance was at par with the Noguchis. But from the midrange to higher frequencies it was not quite as open and transparent. Maybe the Japanese manufacturers use higher quality laminations than the M6 steel used in this Edcor? Since the Hammond 125ESE now sells for about $60 before shipping, the GXSE15-16-3.5K would have been much better value for the money if it were offered with at least two secondary taps.  

Colors in Kanji

Noguchi PMF10WS
Weight = 3.2 lbs

Price = JPY 9,070
Approx. US$80

These two pairs of Noguchi transformers were Akihabara souvenirs from our 2015 Tokyo trip. In spite of the significant difference in price, the PMF10WS and PMF15WS are physically the same in size and weight. Based on specs, the PMF15WS has greater bandwidth and more flexibility for use with various output tubes.

Both OPTs tested well on the bench. Even if the 10khz square wave test does confirm better top end response from the PMF15WS, I could not detect its sonic superiority over the other.  Sonically, the PMF10WS is just as good if you don't need the extensive multi-tap flexibility from its more expensive sibling. In terms of tonal balance, I prefer the warmer presentation of either of the Noguchis over the leaner and more analytical Tango U808.

Noguchi PMF15WS
Weight = 3.2 lbs

Price = JPY12,560
Approx. US$112

I'm not sure if Noguchi accepts international orders. But if you're visiting Tokyo, their basement shop (closed Mondays) at Tokyo Radio Department Store is a must see!