Ashdown CTM-200-RACK User manual

USER MANUAL

Thank you for purchasing your Ashdown Engineering Amplier and welcome to
the family! We really think you’ve made the right choice and know that this
amplier will give you years of great tone and service.
It is a machine though and needs to be looked after, please read
through this user manual which will help you get the most out of
your new Amp and keep it running as long as some of our
happiest and very famous customers.
Please register this product online so we can make sure we give you years of
customer support through our friendly in-house service centre.
Here is where you need to visit to register your product:
http://www.ashdownmusic.com/pages/register-your-product
If you don’t have access to the internet or do not wish to register online you can
do so by post. Please complete the warranty registration card and return it to the
address below :
Ashdown Design and Marketing Ltd, The Old Maltings, Hall Rd
Heybridge, Maldon, Essex , CM9 4NJ, UK
THANK YOU
REGISTER ONLINE

ASHDOWN ENGINEERING - CTM-200-RACK USER GUIDE
INTRODUCTION
The CTM 200R is one of the CTM series of handmade ampliers from our specialist workshop here
in the UK, built to order and built to last!
Quality components are used throughout and when used as designed the amplier will provide
you with years of service.
There are a few points to ensure that the amplier performs as expected, these are listed below :
The amplier is designed to be Rack mounted using the Front and Rear mountings, it is not suf-
cient to try to use the front mountings only!
The amplier is fan cooled , it therefore follows that there MUST be a free ow of air around the
unit, air enters at the front top cover and is exhausted at the rear.
Always ensure the speaker is connected BEFORE you turn the amplier ON!
VU

ASHDOWN ENGINEERING - CTM-200-RACK USER GUIDE
FRONT PANEL FACILITIES
INPUTS - There are two inputs provided of differing sensitivities.
HIGH suits high output instruments input impedance 100k.
LOW suits low output instruments input impedance 100k.
EFFECTS SEND AND RETURN - These 1/4” jack sockets should be used to connect
to an external effects device or pedal board. The EFFECTS SEND output should
connect to the INPUT of the effects unit, and the output of the effects unit should be
connected to the EFFECTS RETURN input.
EQ CONTROLS - Fully passive equalisation featuring bass, middle, treble controls
together with an associated push button that changes the characteristics of each
control.
The bright switch adds extra brilliance when using lower stings of the Master
volume control.
GAIN - This controls the level of the signal sent to the MASTER section. To achieve a
cleaner sound, turn the GAIN control down and the MASTER up. To achieve a richer,
more distorted sound, turn the GAIN control up and the MASTER down.
MASTER - This controls the overall output of the amplier.
MUTE - In the on position, this switch mutes the out put of the amplier (useful for
tuning, etc.).
PRE/POST - This switch determines whether the signal from the DI OUTPUT (see
Rear Panel Facilities) is taken before/PRE the EQ section (down position) or after/
POST (up position).

USER GUIDE
CTM-200-RACK
VU METER - The VU meter tted to the CTM200 has associated with it a 6 position
switch, the rst 4 positions are used to set the bias on the amplier thus removing
the need for access to the amplier internals, the second 2 positions are used to
indicate the power being supplied to the speaker by each pair of tubes.
In normal use the meter should be set to either pair of tubes and it is therefore
possible to check that both halves of the amplier are supplying equal amounts
to the connected speakers. Note that the meter will never indicated zero when the
amplier is switched on.
REAR PANEL FACILITIES
DI OUTPUT - The DI outputs is transformer driven, a PRE/POST switch is provided to
enable selection of PRE EQ or POST EQ signal source. Note that if there is a need to
“ground lift “ the DI this should be done at the connected piece of equipment .
SPEAKER OUTPUTS -2/4/8 Ohm outputs are provided on the rear panel, Use ONE
output socket at a time, closest to the impedance of the cabinet combination you
are connecting.
SPEAKON CONNECTORS MUST BE USED, if jack cables are used and the
connection fails there is a very real possibility of damage to the output transformer
or output valves! Damage so caused will not be covered by warranty.

ASHDOWN ENGINEERING - CTM-200-RACK USER GUIDE
THE VU METER
The CTM 200 meter switch has 6 positions , the rst 4 are used to set the bias on
each individual output tube.
To Check the Bias, connect the speaker and switch on, allow the amplier to warm
up for about 15 mins , Turn Gain and Volume down to zero and depress the MUTE
switch. There now should be almost no noise coming out of the speaker.
Using the switch select each Valve in turn and using a trim tool carefully adjust the
25 turn adjuster to set the needle for that valve as per the diagram above.
Once all 4 valves have been adjusted return the selector to one of the last 2
positions.
WILL STILL WORK
AT REDUCED
POWER
IDEAL SETTING KEEP OUT!
DO NOT SET ANY
TUBE THIS HIGH

USER GUIDE
CTM-200-RACK
If one or more of the valves has NO indication on the meter before suspecting the
output tube check the 315mA quick blow fuses ( There is 1 for each valve located
next to each respective valve). This will require care full removal of the cover to
access the fuse holders.
A continually blowing fuse would indicate either an incorrectly biased output valve
or a defective output. Note. Also blowing fuses can indicate an incorrect load!
VALVE COMPLIMENT :
4 x JJ Electronic KT88
3 x JJ Electronic ECC82
1 x JJ Electronic ECC99
1 x JJ Electronic ECC83

ASHDOWN ENGINEERING - CTM-200-RACK USER GUIDE
SPECIFICATIONS:
Input sensitivity 100mV/300mV nominal
Output Power 200 watts continuous avg into 2 /4 or 8 ohm speakers
Mains supply Externally switchable 115V/ 230V. or 115V/ 240V @50/60 Hz
Power consumption 485W average
DIMENSIONS
17.9” (455mm) W x 5”(128mm) H 3U x 13.8”(350mm) FTR
Rack mountings supplied.

USER GUIDE
CTM-200-RACK
NOTES:

USER GUIDE
CTM-200-RACK
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USER GUIDE
CTM-200-RACK
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