Heathkit W4M Replacement Power Transformer?

[Dukiedook]

It is a Rane product that has transformers that take balanced cables (XLRs) and lets you use RCAs on the other end so you can hook into amps with RCA input cables (So you don't have to splice cables with XLR on one end with RCA on the other). In the setup I had a balanced amp running XLR outputs to a Rane Active Crossover to the Balance Buddy to the 4 Heathkit amps to Altec A7s. It sounded pretty damn good, I can see why people like the Altec A7 speakers biamped with active crossovers.

 

[ggizzy]

Glad it's working. Thanks for updating the thread, I have enjoyed following.

 

[tcdriver]

It is a Rane product that has transformers that take balanced cables (XLRs) and lets you use RCAs on the other end so you can hook into amps with RCA input cables (So you don't have to splice cables with XLR on one end with RCA on the other). ...

Got it. The Balance Buddy provides electrical isolation that can eliminate ground loops that could cause hum. That sounds like an interesting product to know about. Thank you.

In the case of my Heath amplifier, the hum/buzz is purely mechanical, not electrical, so, the rubber grommets, proved to be an effective solution. The grommets: Hillman H# 884634, 1/4 x 1-1/4 x 1/8", purchased at Lowe's.

http://www.lowes.com/pd_423550-37672-884634_0__

 

[tcdriver]

Glad it's working. Thanks for updating the thread, I have enjoyed following.

Thank you for letting me know the thread was useful. It seems that a failed power transformer in the Heath W4 is not too unusual. The Edcor transformer is one solution. I imagine there are other solutions that may be as good or better. I would be curious to know what others have done when confronted with the same problem.

One aspect of this whole project that has not been discussed is the cost of replacing the transformer and bringing the amplifier back to life. From a purely economic standpoint, the better course of action would have been to take the amplifier to the electronic recycler. The transformer alone cost $90, including the shipping and state sales tax. Replacement capacitors, resistors and other miscellaneous parts were about another $30 or so. Add in the value of the 6L6GC output tubes: $125 and the end result is a cost that exceeds the value of the finished amplifier. That being said, I actually enjoyed the process of repairing the amplifier and working out the issues. I learned a few things along the way that are already helping me on my next project. It is hard to put a value on that.

The amp is in my main system sounding very good. :yes:

 

[Dukiedook]

Sure, you could part it out and sell the parts off but you would be missing the sweet sound of a push-pull 6L6 amp you brought back to life. To me there is no amount of money that can replace that experience. I chose these amps pretty carefully after quite a bit of research on what would give me decent bang for the buck to match with my Altec speakers. I was not disappointed.

 

[tcdriver]

Sure, you could part it out and sell the parts off but you would be missing the sweet sound of a push-pull 6L6 amp you brought back to life. To me there is no amount of money that can replace that experience. I chose these amps pretty carefully after quite a bit of research on what would give me decent bang for the buck to match with my Altec speakers. I was not disappointed.

I have owned and used Altec A7 speakers and Heathkit W4 amplifiers, however; I never tried the combination. I can only try to imagine how good your setup must sound.

While I was in the process of replacing the transformer in my W4, I installed the modifications member dcgillespie recommends. Thank you dcgillespie for publishing those modifications. :yes:

The modifications can be found in post #13 in this thread: http://www.audiokarma.org/forums/showthread.php?t=459630&highlight=heathkit+w4

 

[tcdriver]

The following four plots show power supply Voltage VS Time for four different rectifier tubes when used in the Heathkit W4 amplifier. Note the two rectifiers with cathodes show a slower B+ startup voltage with no overshoot. In each of the first four plots: C1, blue trace is the first power supply capacitor, C2, orange trace, is the second power supply capacitor, C3, grey trace, is the third power supply capacitor and K1, yellow trace, is the cathode voltage on the output tubes.

5AR4:


5R4:


5U4:


5V4:

 

[x3workshop]

If you still have the old PT you should contact Gary at TRS up in Maine. He does an excellent job of rewinding to spec. Very skilled and knowledgeable guy.

 

[tcdriver]

If you still have the old PT you should contact Gary at TRS up in Maine. He does an excellent job of rewinding to spec. Very skilled and knowledgeable guy.

That is good information. Is this the place you are referring to? http://www.trstransformers.co.za/

Have you had a transformer rewound? Was it potted? What was the cost?

 

[x3workshop]

That is good information. Is this the place you are referring to? http://www.trstransformers.co.za/

Have you had a transformer rewound? Was it potted? What was the cost?

Try xfrmrs.com

Gary rewound a Mcintosh PT for me with excellent results. Yes it was potted, and is again. I don't know what he would charge for that unit but his rates are reasonable. I have no affiliation, just a happy customer.

 

[tcdriver]

Try xfrmrs.com.

I found it: http://www.xfrmrs.com/id26.html

Gary rewound a Mcintosh PT for me with excellent results. Yes it was potted, and is again. I don't know what he would charge for that unit but his rates are reasonable. I have no affiliation, just a happy customer.

Thank you for the information. They have a price list. A rewind on a Heathkit W4 power transformer is $180 + shipping. My Edcor cost about $90, delivered. The Edcor works just fine, so, I will stick with it.