[Amps] LK500 Question from New Subscriber

[Charlie Young]

Hi Folks:  I am a long time reader of the Amps archives, and finally decided to subscribe.  The amount of expertise available on this list is phenomenal, and several of you have helped me over the years, either with your postings here or by answering questions sent directly by me. All of the help is appreciated. With retirement last year, there is now time to pursue my interest in amplifiers.

 

Recently, I acquired a LK500ZB in an estate sale, and it exhibited the tube socket heating/filament pin solder melting issue that has been described on here. This one has a high/low speed switch factory installed for the blower, and the problem was a cold solder joint on one of the series dropping resistors, causing the cooling fan to run at a very low speed all the time. I replaced the tube sockets, resoldered the tube filament pins, and replaced the plate choke; the amp now runs fine, and puts out ~1500 W when pushed (which I don't do when operating).  However, the fan in this amp is extremely noisy, to the point where it is annoying to use. 

 

Does anyone know what the CFM rating on this fan is supposed to be? It is a NIDEC TORIN TA450 115V Model A30045-10.  The fan is obsolete, and I can find no data from the manufacturer online.  I likely would replace this fan if I could find another with adequate CFM and a lower noise level. 

 

Likewise, I have searched and can find no recommendation for how much air should be directed across a 3-500 when using a transverse airflow like the LK500 and SB220.  I might have missed it, but did look for it.  Does anyone know wht this airflow requirement is in the application? 

 

Currently, I am running the fan with a standard value dropping resistor used by Amp Supply on their high speed position, and there is no way that I am going to slow this fan down and reduce CFM to drop the noise level.

 

Any suggestions or answers to my questions would be appreciated. 

 

73, Chas N8RR  

 

Likewise, I have not been able to find   

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