[Max F]

Quote:

Originally Posted by KMASCII /img/forum/go_quote.gif I've ordered some caps to sample and swap for the WIMA's in my stock LD MKIII. Although I'd appreciate any added clarity and imaging, your comments about a prior lack of treble worry me a bit. I'm not wanting to take my LD any closer to a solid state sound than it already has. If anything, I'd look to toning down the lower high frequencies just a tad. I listen to a mix of rock & acoustic through HD650's with GE 5654 5stars and 6H6n's. These are the tubes I'd finally settled on, and I find this combination just a smidgen bright at times. Other tubes I've tried turned out to be just a little dark or unrevealing for my liking. I guess I'm looking for a more tubey sound, if you will. I wonder if I'll have to revisit some of my other tubes should replacing the WIMA caps expose too much of the highs. I'll try to remember to report back on my experiment and experience.

While I can't comment on the mods i can comment on the tubes. Those 5 stars are on the bright side. Definately check out some Mullard tubes either the EF95 or EF92 varieties (for more tubeyness). Also, look for some Raytheon or Sylvania 6ak5w type tubes for a more balanced, but revealing sound. I would do that before trying the mods - much easier.

 

[SebastianL]

Quote:

Originally Posted by Max F /img/forum/go_quote.gif I would do that before trying the mods - much easier.

I totally agree. If you haven't done some tube rolling, that would be the first thing to do. The only reason why I ventured into this insane modding project, is because I'm such a stubborn ass. If the tube rolling doesn't do it for you, go ahead with the caps. But heed the warning - it's a troublesome job because of the shoebox design.

 

[SebastianL]

Originally Posted by SebastianL:
Subbing the WIMAs with the Jantzens (the first mod I did) made a HUGE difference on the SQ. WOV! The annoying lack of treble (the biggest issue for me) was gone. Now, a lot of clear treble – maybe adding a tad too much emphasis on the high frequencies. But I was so content I was about to stop the modding process. However I had already bought or ordered a lot of other components. Thus, I went on tweaking.
Quote:

Originally Posted by KMASCII /img/forum/go_quote.gif I've ordered some caps to sample and swap for the WIMA's in my stock LD MKIII. Although I'd appreciate any added clarity and imaging, your comments about a prior lack of treble worry me a bit. I'm not wanting to take my LD any closer to a solid state sound than it already has. If anything, I'd look to toning down the lower high frequencies just a tad.

If I haven't done so before, let me correct myself. Now, after the new caps have settled in the Jantzens aren't a tad too bright! Just clearer than the WIMAs.

 

[KMASCII]

Gotcha SebastianL, thanks. This grasshopper needs to learn patience actually

.

My MKIII is the version 2.0 pcb. So I've oredered the 6H30's. I've got about 90-100 hours on the amp. About 50ish hrs on the tubes I'd quoted. I have other tubes from the EF91, 92 & 95 families. One of the reasons I'd settled on the GE 5stars, which are the brightest of any I've used, is the detailing. They've been the best at imaging for me.

Alas, tax return season = upgraditis/mod season for me. But at this time I've got the MKIII paired with LD DAC_1 tolinked to my computer. It's surprising how much cleaner and clearer WASAPI out (Win vista & 7) is compared to ASIO (Win XP). Who'da thunk.

Anyway, great thread, big fan of my MKIII and great work you guys.

Edit: btw, the photos on the Little Dot site are the version 1.0 pcb by the looks of it. My pcb version 2.0 looks different than those posted on their site. I'll post some photos of mine at stock.

 

[KMASCII]

Just to be certain. In the attached diagram these caps are output caps that are in parallel... right?

Cap 1 is, I believe, a Chemi-con 220uf 200v (there's no brand markings on the caps). Cap 2 is the WIMA MKS4 0.68uf 160v.

Thanks.

 

[bigdirty]

hey guys, following this thread Ive had some fun modding my mkIII. I started off removing the parts from the cramped confines and placed them in a cheapo hammond aluminum case. Ive got v2 of the board.
 
Input caps -                 4.7uf Mundorf Supreme
Interstage coupling -     0.22 K75-10 pio   (this mod seemed to be the most bang for your buck)
Output caps -              0.68 K40y-6 pio
Audio Note Tantalum Resistor in the gain section.
Alps Blue Velvet 100k Pot
 
With these mods, listening to music has never been so enjoyable. 
Thanks for this thread.
 
Now I have a question regarding the large electrolytics in the post above.  Im using my mkIII only as a preamp, no headphone use. I emailed David regarding subbing the electrolytic for a film cap and asked if a smaller value could be used. "yes a smaller value can be used"  but when I asked about a specific value I didnt get a reply.  
 
Not using the headphone output, how low can i go with the value of the large electrolytic?   (Chemi-con 220uf 200v) 
 
Ive got some 0.01uf k72, 0.22uf k75, 0.68uf k40, and some 1.0uf film caps kicking around. Can any of these be used?
 
Any input would be appreciated
 
thanks for your time
 
big

 

[SebastianL]

I know this is a little late but FWIW I would say yes, the two caps are in parallel. I'm not that familiar with schematics but judging from the way signal runs it must be a parallel connection.

 

[SebastianL]

Quote:

Just to be certain. In the attached diagram these caps are output caps that are in parallel... right?

Cap 1 is, I believe, a Chemi-con 220uf 200v (there's no brand markings on the caps). Cap 2 is the WIMA MKS4 0.68uf 160v.

Thanks.

I know this is a little late but FWIW I would say yes, the two caps are in parallel. I'm not that familiar with schematics but judging from the way signal runs it must be a parallel connection.

 

[SebastianL]

Bump

 

[Ice Max]

Hey, is there anyway to remove the circuit board from the case without desoldering everything? that seems the only way to get it out for me. I have a MKIII with a v1.0 board

 

[bigdirty]

Quote:

Hey, is there anyway to remove the circuit board from the case without desoldering everything? that seems the only way to get it out for me. I have a MKIII with a v1.0 board

you should be able to pull the board out enough to work on it. remove the potentiometer connector from the front of the board. pull the board out the back. 

 

[SebastianL]

 
Quote:

Quote:

Hey, is there anyway to remove the circuit board from the case without desoldering everything? that seems the only way to get it out for me. I have a MKIII with a v1.0 board

you should be able to pull the board out enough to work on it. remove the potentiometer connector from the front of the board. pull the board out the back. 

That's right. You will be able to work on the board without desoldering. However this method leaves you very little space as the board will not be completely free of the case. There's a risk that you will damage some wires or components. I ended up desoldering the wires to the PSU, the potmeter and the input & output connectors. Trust me this will save you a lot of trouble - otherwise it will be a true PITA.
The wires to the PSU come with a colorcode. Be sure to note where each color go.

 

[Ice Max]

Thanks. I just need to replace the resistors in the back so I can use 6H30 tubes without damaging the amp and killing the tubes prematurely. these have enough wattage and ohms correct? http://www.radioshack.com/product/index.jsp?productId=2062295&filterName=Type&filterValue=1-watt+resistors#

 

[SebastianL]

Quote:

Thanks. I just need to replace the resistors in the back so I can use 6H30 tubes without damaging the amp and killing the tubes prematurely. these have enough wattage and ohms correct? http://www.radioshack.com/product/index.jsp?productId=2062295&filterName=Type&filterValue=1-watt+resistors#

I would't know about this as I have the LD MKIV amp. However the 6H30 tube or 6H6 (my favourite) is an excellent choice. You won't be disappointed. Try to email David at Little Dot, he usually answers very quickly or try the littledot forum which is up and running again.

 

[Stevebol]

Quote:

Hey, is there anyway to remove the circuit board from the case without desoldering everything? that seems the only way to get it out for me. I have a MKIII with a v1.0 board

I ended up cutting all the wires to the transformer and labeling them but I wouldn't recommend doing it. My LD MK III had a hum and one of the large caps had come loose. I'm going to make a larger cabinet for it. A couple wires to the volume pot came loose so I had to cut that.
This is going to be a big pain in the butt but I like the sound of the amp.