drlazybones
New member
n/t
Just bought a used Stereomour 45 on Audiogon - can't wait to get it! [resolved]
- Thread starter drlazybones
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drlazybones
New member
Ok, got the amp set up and playing. I can definitely can hear the smoothness in the mids and treble, almost like a soft roundness in the sound that my SS amp hits a bit sharper, but it's soft in the mid to low bass, very soft by comparison. I can turn the volume up quite loud without getting any kind of listening fatigue - it is very consistently sweet and polite. By comparison, my SS amp sounds quite nice at low and mid volumes, but gets a bit too aggressive sounding when you crank it up. Clear, clean, but aggressive.
I was worried that 1.7 watts wouldn't be enough. It is probably a bit low on headroom, but does play plenty loud. When things get a little complex, I may be hearing some distortion, but I'm not sure - and that may be because I'm running them pretty hard to get the right volume on my ~97db 1W/1M speakers. I'll have to A/B them a few times with my Sugden A21 amp to get a better feel for the difference.
I wonder if an iron upgrade would firm up the lower registers? I'm sure switching to a 2A3 would help in that regard, but I wonder if upgrading to the EXO-03/40mA and EXO-45 or TFA-2004 would deliver the snap I'm looking for. In any case, I can definitely see why people are so impressed by the midrange and treble on a 45, and why they say the bass is a bit polite or reserved. Just thought I would share my immediate impressions.
I was worried that 1.7 watts wouldn't be enough. It is probably a bit low on headroom, but does play plenty loud. When things get a little complex, I may be hearing some distortion, but I'm not sure - and that may be because I'm running them pretty hard to get the right volume on my ~97db 1W/1M speakers. I'll have to A/B them a few times with my Sugden A21 amp to get a better feel for the difference.
I wonder if an iron upgrade would firm up the lower registers? I'm sure switching to a 2A3 would help in that regard, but I wonder if upgrading to the EXO-03/40mA and EXO-45 or TFA-2004 would deliver the snap I'm looking for. In any case, I can definitely see why people are so impressed by the midrange and treble on a 45, and why they say the bass is a bit polite or reserved. Just thought I would share my immediate impressions.
drlazybones
New member
I can report that the imaging and soundstaging is ridiculous, and that plugging in to my P300 Power Plant was a bad idea. I put the amp straight to the wall and it is behaving much better now. Still not quite as crisp down below the belt, but much more respectable now. Listening to Beastie Boys The In Sound from Way Out! which, apart from being plain awesome, is also a great disc to test what an amp can do. I'm very happy with the clarity, and with the way the speakers have really integrated together much nicer than with my other amps.
drlazybones
New member
I tried some Pink Floyd again tonight, Delicate Sound of Thunder. I'm in a bit of a pickle, because I love the hologram this amp creates, amazing, but the bass just sucks compared to my Sugden, which in retrospect, absolutely slams by comparison. I'm sure it has to do to some degree with headroom - the SS amp is 25 WPC, but the Stereomour really doesn't seem to be stressed out or anything when I crank it up - there just isn't any bass to speak of - at least the dynamics just aren't there. I'll have to debate whether I try to upgrade the amp to see if I can shape it up, or just throw in the towel and go look for something else.
tsingle999
New member
I don't have a stereomour but I would try the following if it was my amp:
ni pinstripe tfa 2004 jr or sr. with mq choke.
Change the parafeed cap to something like clarity cap MR and the coupling cap to something premium like vcap (not russian teflons)
Use some sort of power conditioning. There is probably a setting on your power plant that will make it sound better.
These are the things that i did stepwise that gave my sr-45 amps good bass.
Just my opinion and obviously cost a fair amount but it may give you what your looking for?
ni pinstripe tfa 2004 jr or sr. with mq choke.
Change the parafeed cap to something like clarity cap MR and the coupling cap to something premium like vcap (not russian teflons)
Use some sort of power conditioning. There is probably a setting on your power plant that will make it sound better.
These are the things that i did stepwise that gave my sr-45 amps good bass.
Just my opinion and obviously cost a fair amount but it may give you what your looking for?
fullheadofnothing
Moderator
Before going in for major surgery, have you confirmed that you are on the correct impedance for your speakers?
drlazybones
New member
I just checked and yes the OPTs are wired for 8 ohm output. I am very tempted to invest in it, given what it does with the soundstage and imaging etc. Do you all think investing in the EML 45 solid plates would help? I can probably sell the Sophia's for a good chunk of the cost. Or, I might just accept that I need more power and try 2A3s.
Paul Joppa
Moderator
The 8-ohm wiring is on page 37 of the 2010 manual version.
I just remembered, there was an error in the manual discovered a while back, having to do with the plate choke wiring. Check to see that the blue wires go to pin 2 of the 45 socket and the red wire goes to the PSU board; the black wires go to terminals 17 and 19, and nothing else goes to those terminals. Any other arrangement will cause a loss of bass. (The 2A3 wiring is different.)
I just remembered, there was an error in the manual discovered a while back, having to do with the plate choke wiring. Check to see that the blue wires go to pin 2 of the 45 socket and the red wire goes to the PSU board; the black wires go to terminals 17 and 19, and nothing else goes to those terminals. Any other arrangement will cause a loss of bass. (The 2A3 wiring is different.)
drlazybones
New member
The tube socket only has red and black wires connected to it...
Paul Joppa
Moderator
This does not make sense - I am talking about the three wires from the plate choke. Perhaps a picture of the 4-pin socket would clarify?
drlazybones
New member
http://bottlehead.com/smf/index.php?topic=7453.msg73370#msg73370
I found the thread with the correction. The choke was wired according to the original instructions - red to socket pin 2, blue to 17/19L and black to HV+. I'm going to change them to blue to socket pin 2, black to 17/19L and red to HV+ on the power supply board, right?
Here are a few pictures of the wiring:
https://drive.google.com/file/d/0B0pvnD9e2gFvZy04ZWNjcHV6aVk/view?usp=sharing
https://drive.google.com/file/d/0B0pvnD9e2gFvd0pBOGRJNndSdlU/view?usp=sharing
https://drive.google.com/file/d/0B0pvnD9e2gFvVDl1aEhkeUxJT00/view?usp=sharing
I found the thread with the correction. The choke was wired according to the original instructions - red to socket pin 2, blue to 17/19L and black to HV+. I'm going to change them to blue to socket pin 2, black to 17/19L and red to HV+ on the power supply board, right?
Here are a few pictures of the wiring:
https://drive.google.com/file/d/0B0pvnD9e2gFvZy04ZWNjcHV6aVk/view?usp=sharing
https://drive.google.com/file/d/0B0pvnD9e2gFvd0pBOGRJNndSdlU/view?usp=sharing
https://drive.google.com/file/d/0B0pvnD9e2gFvVDl1aEhkeUxJT00/view?usp=sharing
Paul Joppa
Moderator
drlazybones said:
Thanks for finding the thread - I didn't find it last night. You have correctly interpreted the necessary correction. You should find significantly enhanced bass with this fix.
Incidentally, the mnemonic is the old diner term, "blue plate special". Since the Fifties are long gone, many may not be familiar with that phrase - here's wikipedia on the subject:
https://en.wikipedia.org/wiki/Blue-plate_special
drlazybones
New member
Paul, thanks for the tip - that extra inductance makes a big difference! I'm much happier now.
