Where to start - sibilance on analogue replay

Jules_S

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May I call on the collective brains please of TT setup gurus to help me out with an audible problem I have with my setup?

Background - bought the Voyd last December, had a new Origin Live Onyx and Goldring 1042 fitted and set up for me by Tony Whittle (thanks Tony!). Apart from giving it a quick check at the time to make sure it was working, I didn't use it again until about 2 weeks ago, due to problems with the floor in my lounge being so bouncy that it made it quite impossible to play anything safely. I fitted a wall-mounted shelf (Hi-Fi Racks Oak shelf) a couple of weeks ago so now the TT is in daily use.

The issue I'm experiencing is noticeable sibilance on female vocals, and also to my ears, a certain amount of what sounds like midrange distortion, I'd describe it as break-up, as though the cartridge was mis-tracking. The sibilance especially is noticeable even when I'm playing brand new LPs that haven't been out of the shrink-wrap, so I can't attribute it purely to worn LPs that have been damaged by previous playing.

I dug out my Hi-Fi News test LP and protractor and checked everything as best as I can (with my eyesight!). It looks as though Tony did a perfectly good job of the setup - the alignment seems to be correct although bear in mind I'm only using basic tools to check - the supplied alignment gauge and a ruler for the overhang (18mm according to me). The cartridge appears to be parallel to the alignment gauge lines. The downforce was 1.9g according my electronic scales. No idea about azimuth - I can't adjust it anyway with the OL arm, it's a factory-set / adjust job.

Playing the test LP the cartridge passed every test with the exception of the +18dB bias "torture" track (I did notice that on the channel balance tracks there's slight  "bleed-through" (?) between the channels so I'm assuming this is showing up the limited channel separation of the cartridge. I don't have a mono switch on my amp so couldn't check the channel balance on the track where the channels are meant to cancel each other out. Using the resonant frequency tracks I noticed the arm / cart combination experienced the "wobble" between about 9Hz and 12Hz. The one thing I've not checked is the actual bias force being applied as I don't know how I can measure that. It's hanging weight & thread, but there are no markings on the arm to indicate how much force is being applied. Using a blank bit of vinyl I notice a fairly substantial outward movement of the arm when the stylus is placed down on the revolving surface. The arm is set parallel to the playing surface based on an "average" thickness LP, so on the 180g stuff there is a very slight upward inclination from pivot to headshell. 

I keep the stylus clean using the VP sticky stuff (I gave up on the idea of getting a soft brush after my recent posting on suggestions for one). I use a jeweller's loupe to check after one or two sides and clean if necessary. I also use a carbon bristle brush on the LPs and a Zerostat for the static build-up.

So... where do I begin to look for the source of this sibilance and how to correct it? The only adjustment I've made so far is to increase downforce from 1.9g to 2.0g which is now at the upper limit recommended by Goldring - hasn't made any difference to the sibilance (although the bass has taken on a little more solidity and weight, which works for me). Questions:

  • I have read that the Gyger-S stylus profile makes the cartridge very sensitive to alignment - could it really be that a fractional error somewhere could be the cause? 
  • Is it possible that this issue could be caused not by a mechanical alignment issue, but by electronics? My phono stage was refurbished last year with new caps and valve bases, plus new diodes and transistors in the PSU as one had failed, so they were all done. Can a phono stage cause sibilance? The Tube Tech M.A.C. doesn't have adjustable capacitance for MM carts so I can't play with that.
  • Is it possible that there's some actual damage to the stylus? It was a brand new cartridge when fitted and not damaged during that process (I was watching Tony) so it would have had to come from the factory like it. How's Goldring's reputation for quality?
  • Is there a problem with compatibility between the arm and cartridge? Compliance is quoted at 20mm / N static and 10 mm /N dynamic and mass with bolts is 7.3g. OL arms are generally pretty compatible - effective mass of the Onyx is quoted at 12g. I don't know how to work out if this is OK - is it the resonant frequency that's affected by this?

Sorry to bombard with info and questions. There are so many parameters to think about with setup, and every time I think I'm beginning to understand it, it slips away again!

Edit: sorry, should have mentioned - I checked the TT plinth to confirm it's level (it is as far as I can tell with the level I currently have) but I don't have anything lightweight enough just yet to use on the platter to check for level, the suspension is very sensitive to weight so I'm looking for a super-light level to do this. By eye, the platter seems level relative to the plinth. Also should have mentioned I'm still running-in my speakers, and currently have the HF adjuster set to the +1 dB level although I don't know if it will stay like that long-term. I don't hear the sibilance with CD or internet radio though so I'm not convinced it's the speakers at fault, unless my vinyl kit is exciting them in ways the digital can't!

 
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robbie010

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May I call on the collective brains please of TT setup gurus to help me out with an audible problem I have with my setup?

Background - bought the Voyd last December, had a new Origin Live Onyx and Goldring 1042 fitted and set up for me by Tony Whittle (thanks Tony!). Apart from giving it a quick check at the time to make sure it was working, I didn't use it again until about 2 weeks ago, due to problems with the floor in my lounge being so bouncy that it made it quite impossible to play anything safely. I fitted a wall-mounted shelf (Hi-Fi Racks Oak shelf) a couple of weeks ago so now the TT is in daily use.

The issue I'm experiencing is noticeable sibilance on female vocals, and also to my ears, a certain amount of what sounds like midrange distortion, I'd describe it as break-up, as though the cartridge was mis-tracking. The sibilance especially is noticeable even when I'm playing brand new LPs that haven't been out of the shrink-wrap, so I can't attribute it purely to worn LPs that have been damaged by previous playing.

I dug out my Hi-Fi News test LP and protractor and checked everything as best as I can (with my eyesight!). It looks as though Tony did a perfectly good job of the setup - the alignment seems to be correct although bear in mind I'm only using basic tools to check - the supplied alignment gauge and a ruler for the overhang (18mm according to me). The cartridge appears to be parallel to the alignment gauge lines. The downforce was 1.9g according my electronic scales. No idea about azimuth - I can't adjust it anyway with the OL arm, it's a factory-set / adjust job.

Playing the test LP the cartridge passed every test with the exception of the +18dB bias "torture" track (I did notice that on the channel balance tracks there's slight  "bleed-through" (?) between the channels so I'm assuming this is showing up the limited channel separation of the cartridge. I don't have a mono switch on my amp so couldn't check the channel balance on the track where the channels are meant to cancel each other out. Using the resonant frequency tracks I noticed the arm / cart combination experienced the "wobble" between about 9Hz and 12Hz. The one thing I've not checked is the actual bias force being applied as I don't know how I can measure that. It's hanging weight & thread, but there are no markings on the arm to indicate how much force is being applied. Using a blank bit of vinyl I notice a fairly substantial outward movement of the arm when the stylus is placed down on the revolving surface. The arm is set parallel to the playing surface based on an "average" thickness LP, so on the 180g stuff there is a very slight upward inclination from pivot to headshell. 

I keep the stylus clean using the VP sticky stuff (I gave up on the idea of getting a soft brush after my recent posting on suggestions for one). I use a jeweller's loupe to check after one or two sides and clean if necessary. I also use a carbon bristle brush on the LPs and a Zerostat for the static build-up.

So... where do I begin to look for the source of this sibilance and how to correct it? The only adjustment I've made so far is to increase downforce from 1.9g to 2.0g which is now at the upper limit recommended by Goldring - hasn't made any difference to the sibilance (although the bass has taken on a little more solidity and weight, which works for me). Questions:

  • I have read that the Gyger-S stylus profile makes the cartridge very sensitive to alignment - could it really be that a fractional error somewhere could be the cause? 
  • Is it possible that this issue could be caused not by a mechanical alignment issue, but by electronics? My phono stage was refurbished last year with new caps and valve bases, plus new diodes and transistors in the PSU as one had failed, so they were all done. Can a phono stage cause sibilance? The Tube Tech M.A.C. doesn't have adjustable capacitance for MM carts so I can't play with that.
  • Is it possible that there's some actual damage to the stylus? It was a brand new cartridge when fitted and not damaged during that process (I was watching Tony) so it would have had to come from the factory like it. How's Goldring's reputation for quality?
  • Is there a problem with compatibility between the arm and cartridge? Compliance is quoted at 20mm / N static and 10 mm /N dynamic and mass with bolts is 7.3g. OL arms are generally pretty compatible - effective mass of the Onyx is quoted at 12g. I don't know how to work out if this is OK - is it the resonant frequency that's affected by this?

Sorry to bombard with info and questions. There are so many parameters to think about with setup, and every time I think I'm beginning to understand it, it slips away again!

Edit: sorry, should have mentioned - I checked the TT plinth to confirm it's level (it is as far as I can tell with the level I currently have) but I don't have anything lightweight enough just yet to use on the platter to check for level, the suspension is very sensitive to weight so I'm looking for a super-light level to do this. By eye, the platter seems level relative to the plinth. Also should have mentioned I'm still running-in my speakers, and currently have the HF adjuster set to the +1 dB level although I don't know if it will stay like that long-term. I don't hear the sibilance with CD or internet radio though so I'm not convinced it's the speakers at fault, unless my vinyl kit is exciting them in ways the digital can't!
I have just had a very similar issue with my Cantus arm so I used a program to create a custom arc protractor and found that the overhang was 3mm out.

http://conradhoffman.com/chsw.htm

follow the link and click on the third link down from the top. Once the program is open, enter your spindle to pivot distance, choose your protractor (Lofgren or Stevenson) and click on "Typical" then print the protractor to A4 and see how you line up.

Best of luck.

 
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Lurch

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Jules, for bias initially set the ball on the arm roughly 5mm out,  (gap between ball and yoke) then adjust out further as you tweak. With a vtf range of 1.7 - 2. 0g, you shouldn't need to move the ball to more than 10mm from the base of its arm. 

Another thing to consider (as discussed in a recent thread) is the discrepancy in vtf caused by the distance above a record, digital scales weighing pans are. This discrepancy can be around 0.4g as the centre of gravity of the cart & arm system (cart an arm must always be considered together as a system) has changed, potentially in your case from a reading of 2.0g to an actual of 1.6g, hence the sibilance from to low a vtf. 

If possible move the scales off of the platter and onto the plinth, and then raise it up on whatever you can find, such that the weighing pan the stylus sits on is at record height, this will then give you an accurate vtf as it will be set at record surface height. 

You may have to repeat the above vtf procedure as the possible additional downforce needed will change level of the arm to a nose down stance. 

As before if you need any further help/guidance give me a ring. 

 
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Jules_S

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Thanks chaps, that's really useful info. Simon, grateful for your link - unfortunately I'm Mac-only at the moment so can't run an executable (Windows laptop is awaiting rebuild). Also I have no idea if the template is Lofgren or Stevenson - how would I tell? It looks like this (excuse the lo-res image - ripped from t'interweb):

image.png

I have also come across a reviews page of the 1042 on vinylengine and interestingly the first review does mention that too much or too little bias results in a sibilant sound, especially during break-in (which is reckoned to be lengthy). Does this sound plausible? My 1042 probably has around 30-40 hours on it so far, I don't know if that should be bedded-in by now or not? Also interesting to note that the reviewer also runs theirs at 2.0g VTF, which I also found seemed to suit it. There's also a number of mentions of alignment criticality and also of loading capacitance (which I can't adjust) and high output levels. No idea if my phono stage is struggling with the input levels - could this be a factor perhaps?

Incidentally, the identical 1042 I have on my little ProJect Essential (into the bog-standard phono stage of my Pioneer A-400) hasn't shown any similar signs of fussiness - is it because the deck isn't sophisticated enough to show up any issues?

 

Lurch

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As per the extra detail I've added to my above post, the potential for upto 0.4g dis discrepancy in vtf could be contributing to the sibilance as you could be running a differenf vtf than is being displayed once the stylus is back down at record level. 

Also have you tried swapping styli with the one on the project, to see if there's any sonic difference? 

 

Jules_S

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Also have you tried swapping styli with the one on the project, to see if there's any sonic difference? 
Hadn't thought of that (doh). I'll check the VTF again first and try to estimate the bias. It's currently set here - not easy to estimate the distance from a photo I know but I measured it at about 13mm from the vertical "post" to the centre of the ball:

UNADJUSTEDNONRAW_thumb_1852.jpg

 

Lurch

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13mm is to much drop to around 7mm between edge of ball and virtical Post. which should be about right. 

This is mine for a 2g vtf 7mm gap. 

R-12396788-1534437197-3136.jpeg.jpg

 
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awkwardbydesign

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A couple of observations; getting the height of the weight gauge is important, as advised.  Bur some of them are magnetic, which messes up the measurement.  Mine is, so I put a block of polystyrene on it to lift the stylus.  Yours may not need that, but check.

And a smooth section of the LP is no use for bias checking,  It's the drag in the groove which generates the bias, and that varies with record speed and groove modulation. For example a 45 rpm LP with heavy bass would create more drag, so the arm sliding outwards on a smooth bit is normal.

 
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uzzy

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Thanks chaps, that's really useful info. Simon, grateful for your link - unfortunately I'm Mac-only at the moment so can't run an executable (Windows laptop is awaiting rebuild). Also I have no idea if the template is Lofgren or Stevenson - how would I tell? It looks like this (excuse the lo-res image - ripped from t'interweb):

Spenfront.JPG

I have also come across a reviews page of the 1042 on vinylengine and interestingly the first review does mention that too much or too little bias results in a sibilant sound, especially during break-in (which is reckoned to be lengthy). Does this sound plausible? My 1042 probably has around 30-40 hours on it so far, I don't know if that should be bedded-in by now or not? Also interesting to note that the reviewer also runs theirs at 2.0g VTF, which I also found seemed to suit it. There's also a number of mentions of alignment criticality and also of loading capacitance (which I can't adjust) and high output levels. No idea if my phono stage is struggling with the input levels - could this be a factor perhaps?

Incidentally, the identical 1042 I have on my little ProJect Essential (into the bog-standard phono stage of my Pioneer A-400) hasn't shown any similar signs of fussiness - is it because the deck isn't sophisticated enough to show up any issues?
For my two pennyworth .. I had an Origin Live Arm (cannot remember the model but it retailed for over £600 and looks like the one in the picture above - won it at a competition at a Hifi Show.  I put it on in place of the Rega 250 with VTA adjuster and with Michel technoweight) and just could not get on with it - perhaps it was me but setting it up and sorting the bias was a pain in the arse .. when it was all up and running it was just not as solid sounding as the Rega so I swapped it back and gave the Origin LIve to a mate.

Ok to address the problem - if it was cartridge overhang being wrong it would be ok on the first tracks and then be progressively out as the record progresses (or it could be the other way around - but at some points it will be ok) so it would not be sibilant on first and second tracks and then sibilance may come into play as it transverses the record (well that is my opinion for what it is worth the thing is it will not be sibilant on all tracks).  All I do know is I use a protractor ages old for two positions on the record (free in Hifi Sound in the 70s) which i have used on every cartridge I have had (quite a few) and never had a sibilance problem due to cartridge alignment.

Bias and tracking weight are the two main areas for me - ensure the weight set is to the top end of the manufacturers recommended and set the bias to the same weight (if you have a dial up which you don't) and if sibilant then back it off until the sibilance stops.  The bias affect will be even more pronounced the lower the tracking weight in my experience.

As to the turntable making a difference - the answer is no - sibilance is down to the interaction of the arm and cartridge in the groove.

The reviewers loved the Origin Live Arms but sorry I just could not get on with it .. I was using the Rega as a stop gap at the time until i replaced my AT1100 which was falling apart .. I had the Decca in it (which was not ideal - it did have you on the edge of your seat a bit but still did not produce undue sibilance but the Origin Live with the Decca was just plain awful for me.  I have since moved to a Mission 774 and normal service has been resumed (but the Decca is a bit arm fussy).

If you can buy a test record (hifi sound one is the one I use) which is invaluable in setting bias and playing weight.

 
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uzzy

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This comment from Rabski on another thread may be very relevant here too (sorry Rabski if it isn't) he said 

RABSKI said However, I've always treated overhang as the result of the correct alignment, rather than the basis for it. In other words, get the alignment correct (whatever method you choose) and accept that the overhang is what it is once the alignment is correct. Even manufacturers differ on this, though different tonearms do differ in what works best. For mine, I usually just start with about 10mm, but use Baerwald (which seems to give the lowest overall distortion on the Well Tempered) and then leave the overhang as what it ends up as when the alignment is correct.

I'd certainly experiment if I were you. Try all the methods basically, and see what gives you the lowest distortion. I'm still doing that to be honest. I've got mine set up what I thought was spot on, but I noticed last night some distortion on one particularly 'hot' track, though that might simply be the recording overloading the phono stage. Never simple with vinyl is it?

 

mac72

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Start with basics :

- make sure your turntable/platter  is level in every direction ,

- your cartridge compliance is bit low but still within the acceptable range but Goldring requires 150-200pF loading range , what's the setting on your phonostage ? 

If capacitance too high it would cause a pronounced spike in high frequency range which could in effect attenuate sibilance  perception ,

- if mistracking not sibilance , make sure if your alignment is perfect , ask around and try to borrow dr Feickert or similar but also try to adjust stylus zenith - twist of the cartridge a bit - couple degrees  , sometimes stylus zenith could be sightly out and this could rise high frequency THD quite a lot ,

- tracking force , keep close to max recommended,

- bias , try to start with half of tracking force , 

- does mistracking or sibilance happen across whole record or just certain position- beginning , end , etc..

 

mac72

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One more thing , others probably disagree but sticky VP stuff is not very good if stylus is glue bonded - I know few guys lost or disclocated  stylus that way , carbon fibre brush is good enough if you keep your records clean 

 

Jules_S

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Thanks all for the further replies, comments against the various suggestions / observations:

  • @uzzy I'm using the HFN test record already as mentioned in my original posting. The setup seems to check out OK
  • The sibilance is present across the whole playing surface, not just at the end, and it doesn't really seem to get worse towards the end either
  • @mac72 As mentioned, the TT plinth is level (as is the shelf it's sat on) - I still need to double-check the platter once I have a suitable level that won't upset the suspension balance but "by eye" it seems to be level vs the top plate when viewed from the front and from the side
  • @mac72 Phono stage is specified as 47k / 150pF for MM - whether or not mine actually meets the specs I couldn't say and I have no way to test it (nor would I know how). I think I've read that the tonearm cable also has a capacitance of its own - would I add that to the phono stage value to get total capacitance? I can try to find out from OL what that is. To reiterate - the phono stage does not allow adjustment of capacitance, only loading for MCs
  • Zenith seems ok measured by eye - I don't have any alignment tools like the Feickert to confirm this, I'm just using the alignment protractor and my eyes

I will have a go at adjusting the bias tomorrow when I'm feeling fresher and see what difference that makes. Will also re-check the VTF with the scales at playing height, and swap out the stylus with my second 1042 to see if that makes any difference.

Cheers all

Hmm. Here's a further thing. I have just noticed that the valves in my phono stage are different to the ones listed in the specs. The latter mentions one ECC82 / 12AU7 and one ECC81 / 12AT7 per channel, but I have a 12AT7 and a 12AX7 instead. So that means greater gain, but higher noise? Mind you, the PCB is printed with 12AX7 next to each valve base, so that contradicts the printed spec anyway!

Also I note that the input sensitivity on MM is quoted at 0.8mV. If I am correct, the 1042's output is around 6.5mV - could this be overloading the input on the phono and causing problems?

 
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Thanks all for the further replies, comments against the various suggestions / observations:

  • @uzzy I'm using the HFN test record already as mentioned in my original posting. The setup seems to check out OK
  • The sibilance is present across the whole playing surface, not just at the end, and it doesn't really seem to get worse towards the end either
  • @mac72 As mentioned, the TT plinth is level (as is the shelf it's sat on) - I still need to double-check the platter once I have a suitable level that won't upset the suspension balance but "by eye" it seems to be level vs the top plate when viewed from the front and from the side
  • @mac72 Phono stage is specified as 47k / 150pF for MM - whether or not mine actually meets the specs I couldn't say and I have no way to test it (nor would I know how). I think I've read that the tonearm cable also has a capacitance of its own - would I add that to the phono stage value to get total capacitance? I can try to find out from OL what that is. To reiterate - the phono stage does not allow adjustment of capacitance, only loading for MCs
  • Zenith seems ok measured by eye - I don't have any alignment tools like the Feickert to confirm this, I'm just using the alignment protractor and my eyes

I will have a go at adjusting the bias tomorrow when I'm feeling fresher and see what difference that makes. Will also re-check the VTF with the scales at playing height, and swap out the stylus with my second 1042 to see if that makes any difference.

Cheers all IMG_20180503_135032.thumb.jpg.d5c31e733553d9c95e66e21f20e367a7.jpg
Like Lurch has said, it is quite likely you are tracking to light. I now use some old Garrard mechanical scales, from the 60's. With these scales, when compared to digital, they always measure lighter, anything between 0.3 and 0.4gm. All my cartridges have improved no end, when setup using the the Garrard scales.

 
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mac72

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Hmm. Here's a further thing. I have just noticed that the valves in my phono stage are different to the ones listed in the specs. The latter mentions one ECC82 / 12AU7 and one ECC81 / 12AT7 per channel, but I have a 12AT7 and a 12AX7 instead. So that means greater gain, but higher noise? Mind you, the PCB is printed with 12AX7 next to each valve base, so that contradicts the printed spec anyway!

Also I note that the input sensitivity on MM is quoted at 0.8mV. If I am correct, the 1042's output is around 6.5mV - could this be overloading the input on the phono and causing problems?
Worth to investigate , swapping valves won't affect gain by much  but working conditions will change a lot and it might cause distortion 

0.8mV input sensitivity is for MC cartridges , MM you should expect from 3mV up , again definitely worth to investigate 

You need to add cable capacitance , probably above 100pF ,  there will be a peak around 12-13kHz , bit higher than female average sibilance  8kHz - try to use  cable with minimal capacitance  , 

Stylus zenith error would be manufacturing error and not really visible , this could be a couple degrees .

Definitely start with your phonostage valves and input sensitivity first 

When using electronic scales make sure to zero it with cartridge in a fair distance from platform , I use 2 types electronic scales one with lowered platform and standard one and normal mechanical gauge and there is no difference in readings ,

 
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mac72

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Not sure if you mentioned earlier , it is a long post , what's the phono stage?

 

Lurch

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Reading OL specs there phono leads are 50pf per metre so with the 150pf of your PS all should be good at 200pf.

For valves, if you've not got any suitable spares give Robin a PM, he will have a couple spare he may post to you as loaners to experiment with. 

 
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rabski

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It's not unusual for manufacturers to change specs during a production run (re the valves). 12AT7, 12AU7 and 12AX7 are substantially different specifications in various ways and whilst you won't break anything, I would suggest contacting the manufacturer to check what should be fitted (and where). Quite apart from distortion, other things will have an effect. Not least, on most valve phono stages, at least one valve will affect the RIAA equalisation. Circuits are designed around the specs of specific valves, and gain is one of the least important (and determined by more than just the valve itself). Just swapping valves for the sake of it is never usually a good idea.

 

mac72

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Thanks chaps, that's really useful info. Simon, grateful for your link - unfortunately I'm Mac-only at the moment so can't run an executable (Windows laptop is awaiting rebuild). Also I have no idea if the template is Lofgren or Stevenson - how would I tell? It looks like this (excuse the lo-res image - ripped from t'interweb):
measure from hole center to null points :

Baerwald  66.0 and 120.9mm

Loefgren B 70.3 and 166.6mm

Stevenson 60.325 and 117.42 mm 

I  think Origin uses Rega -Stevenson geometry for your tonearm 

 

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