I'll definately keep you posted. One thing I forgot to mention about the Guanzo is the very deep bass is rolled off. As someone else demonstrated with measurement, this is caused by the 0.47uF caps being too low value. On speakers that go deep, this is noticable on some music. I plan to replace those caps by ~2uF when I get around to it and find some suitable replacements that fit.
Bass in general is good and has plenty of presence, but with the stock caps it starts to roll off at around 100hz, with 20hz being down -5dB (credits to bazz_77 for measuring and graphing this).
However, bazz_77 also demonstrated that increasing the .47uF caps to 2.2uF made the frequency response essentially a flat line (actually about +0.3dB @ 20hz)....
If you have a way to get audio into your PC (soundcard, ADC) then you can use RMAA free software to evaluate frequency response and distortion (limited by the quality of your soundcard ofcourse). Other than that, experimentation works I ordered some 2.2uF ClarityCaps, will report results when they arrive.On my Little Bear P-3 I have "Audiophiler MKP" 1.0µF coupling caps (4 of them).
I don't have a way to measure response, but i do lack bass in combo with Sure TPA3116, although I have relatively small speakers.
Flat line response would be nice to have. Any recommendations for low cost replacement of those 1.0µF Audiophiler coupling caps?
Should I go 2.2µf or even 4.7µF?
What kind and values of coupling caps do y'all folks have on your 6N3 based preamps and how are you satisfied with the sound...?
On my Little Bear P-3 I have "Audiophiler MKP" 1.0µF coupling caps (4 of them).
I don't have a way to measure response, but i do lack bass in combo with Sure TPA3116, although I have relatively small speakers.
Flat line response would be nice to have. Any recommendations for low cost replacement of those 1.0µF Audiophiler coupling caps?
Should I go 2.2µf or even 4.7µF?
What kind and values of coupling caps do y'all folks have on your 6N3 based preamps and how are you satisfied with the sound...?
If you have a way to get audio into your PC (soundcard, ADC) then you can use RMAA free software to evaluate frequency response and distortion (limited by the quality of your soundcard ofcourse). Other than that, experimentation works I ordered some 2.2uF ClarityCaps, will report results when they arrive.
Meanwhile the GE 5-star black plate 5670 tubes arrived They are quite short compared to the stock Chinese tubes (left in the picture). If I understand the datecodes right then one of them is from 1963 and the other from 1965. They are not true NOS I'm pretty sure but used, but they measured well and are fairly closely matched. At first turn-on there was a soft crackle over the speakers but as the tubes warmed up that went away and now they work great. Very quiet background and balanced tonality. Will do some critical listening later tonight
The Russian 6n3p-ev's are the same height as the stock Chinese tubes. You should try them as they replaced my GE's.
I soldered on ClarityCap 2.2uF capacitors in place of the stock 0.47uF yellow ones today. The difference is *immediately* apparant. The bass is authorative and deep, The presence has improved a lot. Everything sounds in balance and natural. It is a big improvement.
The 5670's run a lot hotter though, both in visible brightness of the tube glow as in temperature. I wonder if it is designed to run that hot or if this circuit pushes its ratings and makes them live shorter. Anyone know?
Nice, impressive :thmbsp:
Where did You buy those caps, what is the diameter and lenght?
I look to hack my LB P-3, maybe there is something nice and cheap, that will fit on top, cause I have an enclosure that is little less than 10 cm in height, and that 6Z4 tube is higher than 6N3...
BTW, those five star 5670's do look really small
Parts Connexion. They were 3.79$ a piece. I'm not sure the exact dimensions but about 3cm long and about 2cm diameter at its thickest (theyre not round but oval). They come with pretty long flexible leads so can be mounted off-board'ish if needed. Why not let the tubes protrude from the case? Prevents heat buildup and looks nice.
For caps you can go as cheap or expensive as you want. Here is a big comparative review from someone who tested a lot of capacitors, to get an idea: http://www.humblehomemadehifi.com/Cap.html
Yes, I read that already... I usually don't like all that audiophile mumbo jumbo talk, but ClarityCap PX seems reasonable and true, so thanks for recommending them first hand!
I only need to find a distributor who won't charge me $90 shipping fee for 4 pieces of CC PX 2.2µF... :tears:
In my setup I plan to put raspberry pi, DAC, LB P-3, phono stage, two TPA3116 amps, tone stage, PSU, filters and bunch of other small stuff into one enclosure, I will hide tubes inside
I'm still missing some stuff, case itself and I need to do some more tweaks and testing...
Put the tubes near the front behind a window or screen so you can see the pretty glow...
Hey all,
I have the 3 tube version, and I have a recurring issue of the left channel dropping out suddenly.
This can be rectified easily by
1. Switching the power off and on
2. Unplugging and replugging the source
What could possible be causing this? Any ideas? It's quite annoying.