Recorded Cleaning Machnies

@whart, 

Bill what you said is correct.  To amplify, Industry testing has shown that for low kHz machines (< than about 60-kHz), if the flow in the tank is >50% of the tank-volume/min the cavitation intensity drops off very quickly.  As the record spins through the bath, it essentially creates flow, and the book has a calculation that considers the number of records and the rpm, and based on one or other, determines the max rpm or max # of records.  However, there is a minimum rpm recommended of about 0.5-rpm otherwise depending on the UT tank power, the record may be damaged.  Even with the inexpensive Chinese UT tanks, which may not produce advertised power, the bottom of the record is very close to the bottom mounted transducers where the cavitation intensity will be highest.  

@gano, 

Basic rule of thumb for using a single UT tank, is that for best results and best bath management, you want the record to be visually clean before UT cleaning.  So, for a new record, do a simple quick brush with a soft brush to remove visual surface debris, and then into the UT tank.  For used records, you want to perform a pre-clean step before final UT clean, and that can be performed with your process of choice be it a SpinClean or vacuum-RCM.  

@gano, 

I want to buy the one that does most of the job. Sounds like the vacuum based would be it.

For old, used records yes.  However, you still need to perform multiple steps:

Step 1:  pre-clean with a detergent solution; I recommend 0.5% Alconox Liquinox (Amazon.com: Alconox - 1232-1 1232 Liquinox Anionic Critical Cleaning Liquid Detergent, 1 quart Bottle : Industrial & Scientific).

Step 2: rinse with distilled/demineralized water (DIW).

Step 3: final clean with a nonionic surfactant solution, I recommend 0.05% Tergitol 15-S-9 (Tergitol 15-S-3 and 15-S-9 Surfactant | TALAS).  The final clean makes sure this is no residue left from the pre-clean step.

Step 4:  final rinse with DIW

Step 5:  dry

I always recommend this brush -Amazon.com: Record Doctor Clean Sweep LP Vinyl Cleaning Brush : Electronics.  

Couple of things to remember:

• With vacuum RCM, you perform the cleaning, the chemistry, the brush and your technique are what cleans the record.
• The strength of the vacuum provided by the machine determines how much of the detritus released by your cleaning technique get removed.  The stronger the vacuum the more that is removed/sucked from the surface.  But some solution is always evaporated/dried in place.  The strongest vacuums appear to leave about 10% behind while the weaker vacuums appear to leave as much as 30%.  So, the 'quality' of the vacuum RCM can matter.

This vacuum RCM may be current best value - Music Hall WCS-5 Vacuum Record Cleaning Machine.  It has a forward and reverse rotation and a vacuum adjustment, is of decent construction and is made in the USA.  Music Hall is closing it out and you may be able to still get a good price Music Hall WCS-5 Record Cleaning Machine – Upscale Audio , Music Hall - WCS-5 - Record Cleaning Machine; otherwise Music Hall WCS-5 Vacuum Record Cleaning Machine – Audio Advice.  

Good Luck,

@tablejockey,

For the price, the HumminGuru Nova has an updated higher operating frequency 

FYI, the new HG-Nova does not use a higher frequency, it's the same kHz and power as the original.  Download and compare the two operating manuals: HumminGuru Owner's Manual.  The Nova adds some convenience features, uses a wall-wart versus a brick power supply, and makes cleaning 45-records easier.