amplifier

I got an old Rockola 2000x, that had nothing in it when I got it. I put 2 Pyle 6.5 sealed back speakers in the top door, crossed over at 800HZ. I also put 2 GRS 10PF-8 10 inch woofers in the bottom. I purchased a 2x100w TDA7498 amp board from Parts Express, but it does not sound very good. I added a pci sound card to the cpu, but to no avail. Does anyone have any suggestions as to an amplifier. Thanks

I'm not entirely sure of what you are attempting to do here but, jukebox cabinets and speakers are typically matched in the bass section to produce a certain frequency response.

From the spec's of the woofers you chose it seems they would be OK.

The bigger problem here is that juke amps typically have a lot of tone shaping to boost bass response in certain frequencies and roll-off others.

The deepest bass 40Hz are usually attenuated to save amp power and reduce stress on the woofers, and the bulk of the bass boost occurs in the 60-90Hz region. This is typically on the order of 10-14 db and often tied to the position of the volume control. The greatest boost occurring in the lower levels settings. On amps where there is actual audio in the volume control itself most of the boost occurs via taps on the control itself. On newer designs where the volume control is actually all electronic it is done within the circuitry.

Jukeboxes also have an AGC or automatic volume control that makes reasonably sure that all tracks come out at the same level. This also helps with the tone shaping in that the actual position of the volume control can stay at a certain point and not have to be adjusted for each track.

The little amp you bought is simply a power amp w/no tone shaping -that must be added before it.

If you are just going to play tracks from a computer you can have the player normalize the levels of all tracks. Or use an external program such as MP3Gain Most players also have an "EQ" function with both graphic and preset EQ settings.

Be sure that both woofers are in-phase with the same wire from each terminal on a speaker going to the same terminal on the amp. Out of phase speakers with kill the bass.

Rob/NYC

Originally Posted by retired

I got an old Rockola 2000x, that had nothing in it when I got it. I put 2 Pyle 6.5 sealed back speakers in the top door, crossed over at 800HZ. I also put 2 GRS 10PF-8 10 inch woofers in the bottom. I purchased a 2x100w TDA7498 amp board from Parts Express, but it does not sound very good. I added a pci sound card to the cpu, but to no avail. Does anyone have any suggestions as to an amplifier. Thanks

Thank you very much Rob. I downloaded mp3 gain, and that helped a lot. But I am not satisfied with the amp. Do you have any suggestions for an amp???

I can't see why the amp you are using would not be adequate -if- tone shaping is applied -that is what is missing.

A couple of easy options exist:

In all MP3/media players there are software controls for modifying the tonal characteristics of the player's output.

Depending on the O.S. these can be found in the "enhancements", audio or playback panes. In the later versions of Win Media player there are some effective presets including one for "loudness" compensation. Apple Itunes has similar options.

For a hardware solution consider a 1/8 octave graphic equalizer between the comp and and amp.

Have you tried connecting a typical receiver to the speakers in the cabinet or connecting the new amp and computer to external speaker. This might give you a better idea if something is actually wrong, or if it is just a matter of tone shaping.

Again, make sure your speakers are in-phase.

Rob/NYC

Originally Posted by retired

I got an old Rockola 2000x, that had nothing in it when I got it. I put 2 Pyle 6.5 sealed back speakers in the top door, crossed over at 800HZ. I also put 2 GRS 10PF-8 10 inch woofers in the bottom. I purchased a 2x100w TDA7498 amp board from Parts Express, but it does not sound very good. I added a pci sound card to the cpu, but to no avail. Does anyone have any suggestions as to an amplifier. Thanks

When you say "it does not sound very good", what exactly do you mean? Is the audio distorted, bass-heavy, treble-heavy, underpowered, clipping, what? This could help diagnose the problem.

To: Budd Paashaus
Rockola 442
By: Budd Paashaus to alt.collecting.juke-boxes on Fri May 23 2014 03:48 am

BP The problem I have been having is that maybe 2 times out of 5 the
BP display simply cycles through both the odd and even selections without
BP recognizing the thrown pin and returns to the null position, after which
BP it just stops. Then again, it might simply do nothing....the keypads
BP simply just pop back up and the selector wheel doesn't move at all.

Sounds like a write in circuit problem. I'll run it by a friend of mine.

- CAT (n.), Furry keyboard cover.

- C.G. Learn
- Valhalla Home Services! - Telnet://valhalla.synchro.net
- A Gamers Paradise - Over 100 Registered Online Game Doors!

--- Synchronet 3.16a-Win32 NewsLink 1.92
Valhalla Home Services! - Over 100 Online Games! - telnet://valhalla.synchro.net

I agree, it does sound like a write in issue. That would explain why the carousel just rotates through and doesn't stop before returning to home position.

Are there certain selections that work everytime and certain ones that never work or intermittently work?

If that's the case, my best guess is you need to re-align the write-in arm. It's probably throwing some levers and missing others. The procedure for doing that would be in the service manual. Hope this helps!