VOGONS

Search

Common searches

Sound Blaster 16 CT1740 Problem

Topic actions

First post, by borgie83

Posted on 
User metadata
Rank Oldbie
Rank
Oldbie

Hey guys. So I have a Sound Blaster 16 CT1740 which was getting quite hot and also not playing sound out of the left channel. Due to this I replaced the Dac, Amp, Yamaha OPL Sound Chip and 2 larger capacitors located near the volume wheel. All with new parts. I haven't tested it yet as wanted to know if I should also replace the 2 voltage regulators first? Just don't want to power it up and fry the amp etc. Basically I'd like to know if the voltage regulators would cause a sound card to get hot and fry the amp.

Reply 2 of 9, by Jo22

Posted on 
User metadata
Rank l33t++
Rank
l33t++

Hi, not sure what to say. 🙁 If an 78xx/79xx is faulty, it either shorts or passes the full voltage.
These voltage regulators aren't expensive and can be bought in your local electronics shop.
Just be sure to get the right parts. Some stabis can provide 0.5A, 1A or 1.5A (or 2A).
So also better check the suffix, (ex. 7805 vs 7805CT vs 7805G etc.)
Also keep in mind that pinout of 78xx and 79xx is not the same.

"Time, it seems, doesn't flow. For some it's fast, for some it's slow.
In what to one race is no time at all, another race can rise and fall..." - The Minstrel

//My video channel//

Reply 3 of 9, by borgie83

Posted on 
User metadata
Rank Oldbie
Rank
Oldbie
Jo22 wrote:
Hi, not sure what to say. :( If an 78xx/79xx is faulty, it either shorts or passes the full voltage. These voltage regulators ar […]
Show full quote

Hi, not sure what to say. 🙁 If an 78xx/79xx is faulty, it either shorts or passes the full voltage.
These voltage regulators aren't expensive and can be bought in your local electronics shop.
Just be sure to get the right parts. Some stabis can provide 0.5A, 1A or 1.5A (or 2A).
So also better check the suffix, (ex. 7805 vs 7805CT vs 7805G etc.)
Also keep in mind that pinout of 78xx and 79xx is not the same.

Apologies for the delay. The voltage regulators are as follows; AN7805 and AN7809. Both appear to be positive voltage regulators? Could be wrong though. Just thought the sound blasters had 1 positive and 1 negative? 1st VR is 5V and the 2nd is 9V. Both 1A.

Reply 4 of 9, by Jo22

Posted on 
User metadata
Rank l33t++
Rank
l33t++

Hi, yes, seems right to m. The older 8-Bit cards (SB1.x-2) also had -5v, I believe.

"Time, it seems, doesn't flow. For some it's fast, for some it's slow.
In what to one race is no time at all, another race can rise and fall..." - The Minstrel

//My video channel//

Reply 5 of 9, by borgie83

Posted on 
User metadata
Rank Oldbie
Rank
Oldbie
Jo22 wrote:

Hi, yes, seems right to m. The older 8-Bit cards (SB1.x-2) also had -5v, I believe.

So 2 positive voltage regulators being a 7805 and 7809 would be fine to use? Also, is higher or lower ripple rejection better?

Reply 6 of 9, by Tiido

Posted on 
User metadata
Rank l33t
Rank
l33t

Higher ripple rejection is better.

Negative regulator is a small transistor sized thing (TO92 package), 79L05 written on it.

T-04YBSC, a new YMF71x based sound card & Official VOGONS thread about it
Newly made 4MB 60ns 30pin SIMMs ~
mida sa loed ? nagunii aru ei saa 😜

Reply 7 of 9, by borgie83

Posted on 
User metadata
Rank Oldbie
Rank
Oldbie
Tiido wrote:

Higher ripple rejection is better.

Negative regulator is a small transistor sized thing (TO92 package), 79L05 written on it.

Ok great. Thanks mate. What I'm confused about though is that my card appears to have 2 positive voltage regulators and yet I've read about there being 1 positive and 1 negative on Sound Blasters. I'll upload a photo on my voltage regulators for clarification.

Attachments

  • 20190714_093915~2.jpg
    Filename
    20190714_093915~2.jpg
    File size
    667.55 KiB
    Views
    819 views
    File comment
    CT1740 Voltage Regulators
    File license
    Fair use/fair dealing exception

Reply 8 of 9, by Tiido

Posted on 
User metadata
Rank l33t
Rank
l33t

5V one is for positive rails on the opamps and DAC+ADC stuff, -5V one for opamps negative rail and the 9V one is used for the speaker amplifier.

T-04YBSC, a new YMF71x based sound card & Official VOGONS thread about it
Newly made 4MB 60ns 30pin SIMMs ~
mida sa loed ? nagunii aru ei saa 😜

Reply 9 of 9, by Jo22

Posted on 
User metadata
Rank l33t++
Rank
l33t++

Sorry for not replying ealier. Also: Good luck! 😀

"Time, it seems, doesn't flow. For some it's fast, for some it's slow.
In what to one race is no time at all, another race can rise and fall..." - The Minstrel

//My video channel//

Go to top of page Go to top of page
Back to Sound
Close window
Close window