[Rotomoto]

After I spent more time with my LT1364, I concluded that it's too edgy/sibilant for me. I also didn't care for the highish dc offset measurements that I got. I've settled on the LME49720, which has negligeable dc offset <1mv. It also more detailed than the stock opamp with out being too bright. Of course, everyones opinion will differ on sound qualities of different opamps. The LME49720 sounds great and puts out safer dc offset levels.

 

[Brian_the_King]

Thank you for replying Rotomoto, since I posted last I have done a fair amount of research and very likely will end up trying out an LME49720 to compare to the stock op-amp. I wrote my last post because I just recently purchased (have not received) an LDI+, a matched pair of WE408A's and an LT1364, which I obviously did not look into thoroughly enough.

I do have one final question though; could one say that the LM4562/LME49720 is OBJECTIVELY an upgrade from the MC33078? Or is this simply a boutique form of equalization?

 

[Rotomoto]

Yes. And to add, IMHO the LM4562 and the LME49720 do NOT sound the same. I own both, and the LME is the superior opamp.

 

[Brian_the_King]

Quote:

Originally Posted by Rotomoto /img/forum/go_quote.gif Yes. And to add, IMHO the LM4562 and the LME49720 do NOT sound the same. I own both, and the LME is the superior opamp.

Interesting, I heard the same thing on another forum even though the characteristics of the two chips are supposedly identical.

In any case, I purchased an LME49720 earlier today. Now the waiting game

 

[Aynjell]

I've swapped the LT1364 out for the stock op-amp, and damn it I'm impressed with the combo it makes with the EF91. Very powerful, clear, and clean. A combo that typically doesn't come in the same package with this amp. You either get clean, with tight bass, but to have both is just mind blowing. o.o

(not perfect yet, but I think I may have found some of my favorite tubes)

By the way, there's a very militant following behind the LT1364 especially when combined with the gold brand sylvania's... but after rolling around with both, I can't say either really impressed me. These EF91's are eargasms.

 

[V3ng3anc3]

Heh can't wait to try out that combo. I'm still waiting for the amp to arrive, it's stuck in Hong Kong.

My tubes and op-amps are all here already though. I completely did not expect the tubes to be so tiny, thought they would be a bit larger. I wonder if there is any significant difference soundwise between the EF91 and M8083 which is supposed to be a EF91.

Also how do I go about applying DeoxIT on the tube pins? I got the one with the brush. Should I apply it onto a q-tip to keep the brush clean? And from there clean the tube pins.

 

[Aynjell]

Quote:

Originally Posted by V3ng3anc3 /img/forum/go_quote.gif Heh can't wait to try out that combo. I'm still waiting for the amp to arrive, it's stuck in Hong Kong. My tubes and op-amps are all here already though. I completely did not expect the tubes to be so tiny, thought they would be a bit larger. I wonder if there is any significant difference soundwise between the EF91 and M8083 which is supposed to be a EF91. Also how do I go about applying DeoxIT on the tube pins? I got the one with the brush. Should I apply it onto a q-tip to keep the brush clean? And from there clean the tube pins.

No idea. I use a wired brush and just carefully brush the pins until they're nice n' shiny.

Personally, I don't think deoxit would take anything out that my free brushing would and I haven't damaged any tubes doing it.

But I imagine deoxit probably requires a tooth brushing at least.

 

[V3ng3anc3]

Hmm alright, guess I'll try finding some spare toothbrush and try that out.

 

[Aynjell]

Quote:

Originally Posted by V3ng3anc3 /img/forum/go_quote.gif Hmm alright, guess I'll try finding some spare toothbrush and try that out.

Be sure to take before and after pictures and note the time taken. My method takes about 30 minutes for a set of tubes. BTW, vengenace, I have M8083.

 

[V3ng3anc3]

Quote:

Be sure to take before and after pictures and note the time taken.

Sure thing. I might try to use a q-tip for one of my tubes to see how it goes since I don't have a spare toothbrush or brush atm.
Quote:

My method takes about 30 minutes for a set of tubes.

o.o That seems kind of long, I would have imagined it to take around 10 mins for a pair.
Quote:

BTW, vengenace, I have M8083.

Ohhh...haha. That's good to know, thought we had different tubes.

 

[V3ng3anc3]

Alright so I tried to clean my CV4010 tube with deoxit and q-tip, here are the results.

Before:
Imageshack - p1010695d.jpg
Imageshack - p1010700z.jpg

Midway Through:
Imageshack - p1010706a.jpg
Imageshack - p1010707nu.jpg
This was after I waited a couple of minutes for the deoxit to settle then attempting to clean it was a q-tip. Didn't really do much.

After:
Imageshack - p1010708yb.jpg
Imageshack - p1010710z.jpg
This is the final result after I gave up using the q-tip and just straight up used the deoxit brush, brushing it repeatedly. It did a lot better job but I think I definitely need some kind of brush.

Almost forgot, for the whole ordeal I spent nearly 25mins including waiting for the deoxit to settle.

 

[Aynjell]

While my process requires a great deal of finnesse, the results are staggeringly better. I'll take some before and after shots of my tubes after some wire brushing. One thing I will say is I'm not using a wire brush like you'd use to remove tar from a fender well or something, something a lot more like a too brush but with wires coming out of it. It's very thin and delicate, so it's not going to bend or break the pins...

Only concern I have is I may be removing some type of coating on the pins, but I'm hesitant to believe I can scrape off anything that's supposed to be there. None of my tubes are gold pinned that I know of.

 

[V3ng3anc3]

Just received my Little Dot I+ about 30mins ago! Burning in the stock tubes now. :]

 

[PatOMalley]

A small file works great.
run it across the pins, just a a slight scrape till you get the shine. THEN deoxit.

Quote:

Originally Posted by V3ng3anc3 /img/forum/go_quote.gif Alright so I tried to clean my CV4010 tube with deoxit and q-tip, here are the results. Before: Imageshack - p1010695d.jpg Imageshack - p1010700z.jpg Midway Through: Imageshack - p1010706a.jpg Imageshack - p1010707nu.jpg This was after I waited a couple of minutes for the deoxit to settle then attempting to clean it was a q-tip. Didn't really do much. After: Imageshack - p1010708yb.jpg Imageshack - p1010710z.jpg This is the final result after I gave up using the q-tip and just straight up used the deoxit brush, brushing it repeatedly. It did a lot better job but I think I definitely need some kind of brush. Almost forgot, for the whole ordeal I spent nearly 25mins including waiting for the deoxit to settle.

 

[V3ng3anc3]

Quote:

A small file works great. run it across the pins, just a a slight scrape till you get the shine. THEN deoxit.

I'll have to give that a try, thanks Pat!