[tomb]

Quote:

Originally Posted by TeraHz /img/forum/go_quote.gif Hi, I've been listening to the SSH for a week now and I believe the low freqs. are distorted. My signal follows this path: FLAC -> y2 -> SSH -> Grado SR80. There are not EQs in software. Is anyone experiencing similar results?

I can't speak for everyone, but no - I've not heard this except for a bit during initial break-in. The coupling capacitors may sound like they're distorting in the first few hours until they clear up. Other than that, no.

 

[PJPro]

I've almost completed the kit. Progress was halted when I realised that the allen bolts used for the heatsinks are not metric.....and I only have metric keys. Damn!

I've also had a bit of difficulty with the LEDs. Why are the holes in the PCB soooo small? They caused the heat shrink to foul. It would seem that they could have been a lot bigger.

I also had a fright with glueing the sockets together. I couldn't get the tubes in after glueing! I used the lead from a 5W resistor to free them up. They're still tight but I can get the tubes in now.

 

[tomb]

Quote:

Originally Posted by PJPro /img/forum/go_quote.gif I've almost completed the kit. Progress was halted when I realised that the allen bolts used for the heatsinks are not metric.....and I only have metric keys. Damn! I've also had a bit of difficulty with the LEDs. Why are the holes in the PCB soooo small? They caused the heat shrink to foul. It would seem that they could have been a lot bigger. I also had a fright with glueing the sockets together. I couldn't get the tubes in after glueing! I used the lead from a 5W resistor to free them up. They're still tight but I can get the tubes in now.

Sorry you're having trouble - but except for the 4-40 screws (ironically, the English system), these things were specifically noted in the Build thread.

 

[PJPro]

No real problems, just minor inconveniences.

I've not bothered with a allen key. I simply applied some pressure to the bolt with my finger and tightened up the nut. With the locking washer it doesn't need to be that tight and using this approach has made sure that I don't over tighten the MOSFETs.

I am a little worried with the amount of heat I've had to put into some components to get the solder to flow......I'm assuming this is due to the large ground plane?

 

[tomb]

Quote:

Originally Posted by PJPro /img/forum/go_quote.gif No real problems, just minor inconveniences. I've not bothered with a allen key. I simply applied some pressure to the bolt with my finger and tightened up the nut. With the locking washer it doesn't need to be that tight and using this approach has made sure that I don't over tighten the MOSFETs. I am a little worried with the amount of heat I've had to put into some components to get the solder to flow......I'm assuming this is due to the large ground plane?

Yep. It takes more heat for those pads that are connected to the ground plane.

 

[Skat]

I just stumbled across the SSMH and would like to try and build one. In my research it seems that there are no part kits. All parts need to be bought via the BOM, part by part. I saw it mentioned, around late July, getting them going again but nothing since. Is this due to the scarcity of the tubes? Is there a substitute for the tubes? Is my assessment of the situation correct or do I need to do more research? My apologies if this has been covered over the last 200+ pages.

Thank You Very Much,
Steve

 

[revolink24]

Largely, AFAIK, it is mostly due to the scarcity of the tubes. A substitute tube is in the works. The custom case has sold out, you would need to drill the holes yourself. The PCB and several other parts are here. If you want the bill of materials for the PCB SSMH, don't use the Millett original, use the BOM here. Also, I at least recommend reading a good chunk of this thread, there is useful information on issues other people have experienced.

Cheers.

 

[revolink24]

Sorry, double post.

 

[Skat]

Thanks for the info. Do you have a feeling for when the substitute tubes will be found? I think I'll wait for the substitute, if it is not long in coming (6 months or so?).

Thanks,
Steve

 

[the_equalizer]

Quote:

Originally Posted by revolink24 /img/forum/go_quote.gif Largely, AFAIK, it is mostly due to the scarcity of the tubes. A substitute tube is in the works. ... Cheers.

Actually there's been a circuit using an alternate tube for some time. Search the thread for 12SR7.

Cheers!

 

[Juaquin]

Quote:

Originally Posted by tomb /img/forum/go_quote.gif Yep. It takes more heat for those pads that are connected to the ground plane.

I can attest to this - I had to heat the ground plane for nearly 10 seconds sometimes to get the solder to flow. It's best to do as many of the grounds at the same time as you can, while the plane is heated. This might also help those having hum issues - if one of your ground connections is not well made it might result in a broken up ground and humming.

 

[luvdunhill]

Quote:

Originally Posted by Juaquin /img/forum/go_quote.gif I can attest to this - I had to heat the ground plane for nearly 10 seconds sometimes to get the solder to flow. It's best to do as many of the grounds at the same time as you can, while the plane is heated. This might also help those having hum issues - if one of your ground connections is not well made it might result in a broken up ground and humming.

Sometimes it can be helpful to heat up the PCB with a heat gun, usually I do this. Otherwise, I have another iron with a fatter tip and a few more watts handy so I don't have to swap tips out of my main iron.

 

[PJPro]

OK. Now finished and listening to the amp.

Rig: Vista PC->FLAC->Foobar2K->ASIO4ALL->Xfi Xtreme Gamer->Optical->Modded Beresford TC-7510->SSMH->SR80s.

Initial impressions (less than 30 mins) are good. A bit harsh at times, but I'd expect things to mellow over time. No hum to report but I do appear to have some crackle on the pot.

Also, the slightest turn of the pot takes the volume to unbearable. I went for the 50K resistors for R16/17. Looks like 100K might have been a better bet? If so, I'll swap them around before finally sealing the box.

Oh and the LEDs work a treat! I went for blue. I'll post some pictures shortly.

 

[tomb]

I ran out of tested tubes for awhile, but have more available now. There are also a few cases (4) where I manually drilled and punched the case lid, although the endplates were machined by Hammond.

Still trying to decide whether to offer more kits. If I do, they'll be without power suppies and will probably be limited to 20 or so. Tubes are about 1/3 of what I had and I continue to have a very high rate of rejects - more than I've seen of any other tube. About 3 out of 10 either have dead shorts or are below minimum output on one set of plates.

 

[PJPro]

Quote:

Originally Posted by PJPro /img/forum/go_quote.gif Also, the slightest turn of the pot takes the volume to unbearable. I went for the 50K resistors for R16/17. Looks like 100K might have been a better bet? If so, I'll swap them around before finally sealing the box.

I've just taken a look at the BOM, which states that 100K should be used for R16/17 when using highly efficient headphones. Are the Grado SR80s regarded as highly efficient? I'd hate to remove the 50K resistors to put in the 100K resistors only to find myself wanting to put the 50K back.

So, should I go for the lower gain (100K) or stick with the higher gain (50K) and put up with the micro adjustment of the pot?