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Today's Featured Head-Fi Blog: A Japanese headfier's monologue (Sasaki)
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Based on your experience, how would you compare reasonably modded 708B (new NOS tubes, signal wiring, ALPS stereo pot, Input/Output Resistors and new inter-stage coupling and hp output caps) to let say ….
Darkvoice 336i
Little Dot 2++ (or any other variations of Little Dot)
Cayin HA-1A (I know, this is completely unfair considering the price difference)
Based on your experience, how would you compare reasonably modded 708B (new NOS tubes, signal wiring, ALPS stereo pot, Input/Output Resistors and new inter-stage coupling and hp output caps) to let say ….
Darkvoice 336i
Little Dot 2++ (or any other variations of Little Dot)
Cayin HA-1A (I know, this is completely unfair considering the price difference)
Unfortunately my 708B is the only amp that I have experience with so I can't give any useful comments. However, in a few weeks I'm planing on loaning my modded amp to a well-known head-fier to be included in his massive amp review. That will provide you with the info that you seek.
That is great. I am looking forward to the review. I plunged in myself since I posted the question and ordered one for myself. It should be here in another week. I am also about to order parts for the majority of the mods and I have couple of upgrade tube sets on the way (NIB JAN 5670W, Amperex A-Frame 6DJ8, and 6N3P-EB).
Where did you get your knob for ALPS? I know that the primary concern is the sound quality, but the one from Radio Shack that everybody used is just plain butt ugly! The original knob looks rather decent, how come nobody tried to reuse is (I am sure it would require some retooling but still)?
Could someone tell me what is the diameter of the original knob? I found a very nice and reasonably inexpensive knob (KILO International JD90) but I am not sure if it is big enough. Shaft socket seems to be a good match: http://www.kilointernational.com/kno...jd_series.html
I'm also looking forward to seeing how it compares to some of the other amps now. I got that knob from Rat-Shack too, PN: 274-407. The original knob is made out of plastic and felt pretty cheap. It was made for a splined shaft and the ALPS I got had a smooth shaft so I couldn't use it. I like the contrast of a black knob against brushed aluminum much better anyways. I threw that vol knob away so I don't know how big it is, but the circular pocket on the front panel is around 1.302" (~33mm) diameter on my amp for reference, so that JD90 would be too small to fill it up fully.
I finally found a source for a good size knob. It is somewhat on the expensive side ($12 + $5 S&H) but reasonable considering they are machined out of solid chunk of aluminum and great looking. The diameter is 1.4" (36.2mm) what should be a good fit (slightly bigger than the original knob):
Those are some nice looking knobs. It's a shame the K1.4 is a bit too big and the K1.1 is a bit too small. I looked around some and I only found a few 30mm aluminum knobs, but no 33mm ones. The best fit would be the KB-BE-32 from VT4C Studio, but it's made out of wood though. Man if I had a metal lathe here I'd just make you a custom one.
Why do you think that a larger knob is a problem? I understand that the knob would not fit inside the original recess, but if you mount it so it just slightly clears the flat surface of the enclosure, it would look good. Am I missing something?
Nah, I didn't mean it'd be a problem going with the larger knob, since it'll completely cover up the pocket anyways as you said. I just meant that it's a shame you can't get one the exact size that the pocket was milled out for.
I didn't read through all of the mod but I hope the output caps were increased in size as the knee of the .22 would hold down the bass and there is no need for 1K resistors on the input but 200 to 400 ohm would work fine. The higher input resistor will curtail the highs some. I would use Riken Ohm as much as the tants. I have used many tants from the better tants (before they were no longer made in Japan and were nonmagnetic) to the later and not as good Audio Note tants and the Riken hold their own just fine if not better.
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John aka Jam and Jama Photo gallery at:www.pbase.com/jamato8
The one constant in life is change, so will that change?
Feel with your own heart, see with your own eyes and hear with your own ears. Sand is sand no matter where it is found. Listening to: The Greatful Dead, The Closing of Winterland 1978, Fillmore West 1969, Lucinda Williams, Leonard Cohen Amps I am currently listening with: RSA B-51, iBasso T4, SR 71A, new Xin Reference, Lisa III with Lab Power supply Favorite headphone: Ultrasone Ed. 9 #1010 Portable amp ratings: *1. SR-71A *2. iBasso D3 *2b RSA Predator *3. Xin Micro *5 iBasso P3 *5b. Mini IV *6. D1 iBasso upgraded amp *6b. iBasso P2 (upgraded opamps) *8. C & C Box (good decay, tilted up high frequency, slightly synthetic) *9 iBasso T1 *10. iBasso T2 *11. XTRA X-1 (warm not neutral, very musical) *12. LD M+ These amps are enjoyable to listen to and present a slightly different interpretation of the musical signal. Portable monitor ratings: *1. PortaPros, KSC35 (modified-a great value) *2. Amadana P-117 bamboo *3. UM2 (respond to top quality amplification but I don't enjoy their sound) *4. OVC 8+ Source: iRiver H130,140, D303 optical out, D-EJ955, D-EJ1000, D-EJ2000, 25s, 25, D-303, D-777 and others (optical out if available) Digital Conversion: Altoid tin Monica Dac I, Altoid tin Monica II Asynchronous Reclocking Dac. Headphone Amplifiers: iBasso D1, IV Micro, IV Mini, Xin Reference, SM3B, SuperMacro V LE, SM3 V6 Xin (IV all switches), XRTA X-1, LD Micro +, LD Micro Tube, C&C Box, iBasso P1, P2, D1, D2, Woo 3 Modified-Siemens 6922 driver, 7236 power tube, Woo 6 Modified Pseudo dual PS - Headphones: Ultra Ed. 9, HD650, Ultrasone 750, HFI780, PortaPro modified, KSC35, Equation RP-21, Westone UM2
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