541774
15
Zoom out
Zoom in
Previous page
1/20
Next page
SVT-VR Bass Guitar Amplifier
15
Changing the Tubes
Tubes wear out in direct proportion to how often and how hard you use the amplifier. Power tubes
should be checked at least once a year – more frequently if you use the amplifier nearly every day.
When power tubes wear out, the amplifier will begin to grow weak, lack punch, fade up and down, or
lose highs and lows. Power tubes work together in a push/pull configuration and should be replaced
at the same time with matched or balanced tubes. Your dealer can recommend the best replacement
tubes for your amplifier.
Preamp tubes aren’t worked as hard as power tubes and typically last longer. When a preamp tube
wears out, the amplifier may squeal, get noisy, lose gain and sensitivity, or just quit working. A service
center can determine which tube(s) may need replacing.
To get to the power tubes in the SVT-VR, the rear screen must be removed and the tube retainer(s) must
be moved out of the way. Qualified service persons may follow these steps to change the tubes:
•Turntheampoff,unplugitandletitcoolforatleast5minutes.
•Removethescrewswhichholdtheperforatedmetalscreentotherearofthecabinet.
•Settheperforatedmetalscreenaside. 
•Removethetuberetainer(s)byliftingthemoffthetube(s)andmovingthemtooneside.
•Graspthetubeatitstopandgentlyworkitoutofitssocketbyrockingitslightlybackandforthas
you lift up on it.
•Wheninsertingnewoutputtubes,alignthetabinthetube’splasticbasewiththeslotinthesocket
and press the tube gently but firmly into place by pushing down on its top.
•Replacetheperforatedmetalscreenandscrews.
•Poweruptheamplifierandletitsitforatleast20minutes.Biastheamplifierasdirectedinthe
section below.
Setting Tube Bias and Balance
Tube Bias:
Allow the amplifier to warm up to proper AC line voltage for at least 20 minutes. With no signal
present, adjust each bias control until its adjacent LED illuminates.
The Bias 1 control affects the three power tubes on the left (as viewed from the rear). The Bias 2
control affects the three power tubes on the right (as viewed from the rear).
Balance:
Insert a 40 Hz signal into the amplifier. Adjust the volume control for approximately 25VRMS output.
Slowly adjust the balance control until its adjacent LED illuminates.
15


Need help? Post your question in this forum.

Forumrules


Report abuse

Libble takes abuse of its services very seriously. We're committed to dealing with such abuse according to the laws in your country of residence. When you submit a report, we'll investigate it and take the appropriate action. We'll get back to you only if we require additional details or have more information to share.

Product:

For example, Anti-Semitic content, racist content, or material that could result in a violent physical act.

For example, a credit card number, a personal identification number, or an unlisted home address. Note that email addresses and full names are not considered private information.

Forumrules

To achieve meaningful questions, we apply the following rules:

Register

Register getting emails for Ampeg SVT-VR at:


You will receive an email to register for one or both of the options.


Get your user manual by e-mail

Enter your email address to receive the manual of Ampeg SVT-VR in the language / languages: English as an attachment in your email.

The manual is 1,8 mb in size.

 

You will receive the manual in your email within minutes. If you have not received an email, then probably have entered the wrong email address or your mailbox is too full. In addition, it may be that your ISP may have a maximum size for emails to receive.

The manual is sent by email. Check your email

If you have not received an email with the manual within fifteen minutes, it may be that you have a entered a wrong email address or that your ISP has set a maximum size to receive email that is smaller than the size of the manual.

The email address you have provided is not correct.

Please check the email address and correct it.

Your question is posted on this page

Would you like to receive an email when new answers and questions are posted? Please enter your email address.



Info