Some advice and tips, Assistance, Cleaning and upkeep – darTZeel Audio CTH-8550 User Manual
Page 14: What not to do

darTZeel CTH-8550
User Manual, version 1.0
Page 14 of 15
11. Some advice and tips
11.1. Cleaning and upkeep
The darTZeel CTH-8550 has not only been designed to 
provide you intense moments of musical pleasure; it 
also has been designed to withstand the rigors of 
time – assuming that you take proper care. 
The entire Swedish-steel case functions as a heat 
exchanger, while the two internal lateral heat sinks 
regulate and maintain the correct temperature. The 
vent slots provide heat dissipation, but they do not 
communicate with the inside of the machine. 
Therefore, the CTH-8550 is virtually dust-proof. 
It is
not
recommended to clean internal parts.
Actually, we do not recommend ever removing the 
top cover!
As for the external parts of your machine, a soft cloth or 
even a dust brush will be completely adequate. 
In case of fingerprints, a gentle rub with a cloth 
soaked in isopropyl alcohol should be sufficient. 
Just bear in mind, however, that the simplest things are, 
more often than not, the most efficient. 
We personally find that a spot of mild soap on a wet 
soft cloth is the best method most of the time. Try 
for yourself! 
As you have certainly guessed, we confirm that it is 
strongly recommended to 
never use acid
to clean
your gear. Acid is very corrosive and could react 
with the front plate’s anodized coating. 
Furthermore, acid is very corrosive for the skin, too… 
If you follow these few elementary rules, you will 
be assured of having a very nice-looking machine 
for years to come. 
11.2. What not to do
Our advice and recommendations have been 
intentionally placed close to the end of this user’s 
manual. That does not mean that they are of only 
minor importance – quite the contrary. 
We just thought that the following points are not 
directly involved in the everyday use of your 
amplifier. 
However, operating the darTZeel CTH-8550 calls for 
certain precautions. 
The few but important warnings are the following:
Never, ever attempt to short-circuit the Speaker 
Binding Posts.
 Repeated short circuits will lead to permanent damage
to the corresponding output stage.
When bi- or tri-cabling, be especially careful when 
connecting the cables. If you inadvertently cross 
the polarity of one run regarding the other(s), 
you will make a perfect short circuit. This can 
easily destroy the corresponding output stage! 
The warranty will be partially or totally void 
in the event of non-compliance with the 
above!
 Never forget to power off your darTZeel CTH-8550
before connecting or disconnecting any source or 
loudspeakers. 
 Never use a “contact enhancer” such as silver
paste on the input terminals or speaker binding 
posts, as this may cause a short circuit and 
catastrophic failure. 
12. Assistance
If you need any commercial or technical information 
about the darTZeel CTH-8550, or if you have any 
difficulties or enquiries, please contact us by email 
at 
You can of course write us at the following address:
darTZeel Audio SA 
2, chemin Louis-Hubert 
CH-1213 Petit-Lancy 
Geneva/Switzerland 
 
We also invite you to visit our website at 
www.darTZeel.com
We wish you countless hours of musical delight 
with your CTH-8550. We hope that you will have 
no further need to read this manual, except for the 
pleasure… 
Your darTZeel team
