Turntable not spinning fast enough on 45 Options

[powerstone05]

I have (now) a GemSound BJL-1150. The problem I'm having is that the 45 rotation is quite slow and is noticeable in playing. The 33 seems to be fine though. I checked the belt and it's still in working order. Any ideas?

[powerstone05]

Probably a stupid question but I know that playing a 33 LP at 45 and then slowing it down compromises the quality, but wouldn't the same thing happen if I play a 45 at 33 and then speed it up? (Yes I do plan to record some records off of it)

[Glenn Gundlach]

Probably a stupid question but I know that playing a 33 LP at 45 and then slowing it down compromises the quality, but wouldn't the same thing happen if I play a 45 at 33 and then speed it up? (Yes I do plan to record some records off of it)

If the speed is only off a few percent 'tweaking' it in digital is OK. I don't know how big a problem it is but the RIAA curves crossover points should really track the speed difference but it's probably more of an OCD thing.
Question: You say the speed control is still slow when at +10%, is the speed _range_ about right? Does it seem to go to -20% less ? A 20% span would be a little more than 3 semitones.

G²

[powerstone05]

Probably a stupid question but I know that playing a 33 LP at 45 and then slowing it down compromises the quality, but wouldn't the same thing happen if I play a 45 at 33 and then speed it up? (Yes I do plan to record some records off of it)

If the speed is only off a few percent 'tweaking' it in digital is OK. I don't know how big a problem it is but the RIAA curves crossover points should really track the speed difference but it's probably more of an OCD thing.
Question: You say the speed control is still slow when at +10%, is the speed _range_ about right? Does it seem to go to -20% less ? A 20% span would be a little more than 3 semitones.

G²

Well I just posted a similar question over at the Audacity forums, and used the formula to determine the actual RPM. I did a test with a 12" single I have and put it on 45 with pitch adjustment at max (10%). The result was approximately 44.826 RPM, which bugged me, so close but not there. But its enough that I can notice.

[mzil]

You can increase the speed slightly by applying a twist to the belt before it loops around the pulley. [One high-end TT maker a decade or two ago, Well-Tempered, used to do this as a normal course of action, claiming it reduced flutter.] Depending on if you flip it around one way or the other [top edge flipped away from the main platter vs toward the platter] the belt may have a tendency to ride around the pulley rather high or rather low. Try both ways and see what gets you to the speed you want.

[DonP]

You can increase the speed slightly by applying a twist to the belt before it loops around the pulley

Unless the problem is slipping, I don't see how this would increase the speed. The ratio between capstan and platter pulleys will be the same.