Inherited some audio equipment and need advice

[jcrowde3]

Due to unfortunate events, I inherited some audio equipment from my cousin and I would like to create some kind of audio setup with it.

List of items:
2 Crown D150As
Hafler 220
2 JBL Model 4312 Control Monitor
Denon DP-45F Turntable
Crown 460 CSL

I realize that the Crowns the the Hafler are all power amps. Is there one that should be used over the other?

 

[shadyJ]

Between those amps, I would go with the Hafler. But you may want to try them all out to see which has the lowest noise floor.

You still need a pre-amp, which it doesn't look like you have. You will need a pre-amp that has phono/line inputs. Maybe something like this will work for you, it can handle the turntable along with one other source.

 

[jcrowde3]

I have an onkyo sr494 receiver laying around. Would that work as a preamp if I also wanted to hook this system to a TV?

Between those amps, I would go with the Hafler. But you may want to try them all out to see which has the lowest noise floor.

You still need a pre-amp, which it doesn't look like you have. You will need a pre-amp that has phono/line inputs. Maybe something like this will work for you, it can handle the turntable along with one other source.

 

[lovinthehd]

I have an onkyo sr494 receiver laying around. Would that work as a preamp if I also wanted to hook this system to a TV?

The Onkyo 494 isn't suitable for use as a pre-amp as that Onkyo only has pre-outs for a sub (you'd want at least L/R speaker pre-outs generally to use an external amp). The avr may be more friendly to using with video, tho, and you could just use a phono pre-amp (aka phono stage) for the tt into one of the avr's line inputs. ART makes some good affordable phono pre-amps too.

 

[TLS Guy]

Due to unfortunate events, I inherited some audio equipment from my cousin and I would like to create some kind of audio setup with it.

List of items:
2 Crown D150As
Hafler 220
2 JBL Model 4312 Control Monitor
Denon DP-45F Turntable
Crown 460 CSL

I realize that the Crowns the the Hafler are all power amps. Is there one that should be used over the other?

I would NOT use the Crown D 150s.

They were among the first, if not the first direct coupled amps, where the power transistors are directly connected to the speakers. They had no protection against DC offset. So if a power transistor blows, the whole DC voltage is sent through the speakers, with smoke and flame. The transistors are now old and so very dangerous. I specked two of those in a big dance hall installation when they were the latest rage.. It was a biamped active installation, and on opening night a transistor failed with a dramatic takedown of the top end of the right channel. So they were replaced with BGW amps.

 

[jcrowde3]

I would NOT use the Crown D 150s.

They were among the first, if not the first direct coupled amps, where the power transistors are directly connected to the speakers. They had no protection against DC offset. So if a power transistor blows, the whole DC voltage is sent through the speakers, with smoke and flame. The transistors are now old and so very dangerous. I specked two of those in a big dance hall installation when they were the latest rage.. It was a biamped active installation, and on opening night a transistor failed with a dramatic takedown of the top end of the right channel. So they were replaced with BGW amps.

So are all the amps trash or are the other two amps worth anything?

 

[Eppie]

So are all the amps trash or are the other two amps worth anything?

The manual for the Hafler is still available here. Looks like it was kit assembled. Powered with MOSFET transistors and rated at 115W per channel. Circuit diagram is in there so it can still be serviced. That should be enough power to drive most speakers. This amp might appeal to those that are into vintage gear.

Manual for the Crown 460 is here. Looks to be more like professional gear. More power than the Hafler at 200W/ch (8 ohms) but it uses 1/4" phone jacks so you'll need to dig up proper cables. It supports both unbalanced (RCA) and balanced (XLR) connections on the input. Make sure the switch on the back is set to Stereo and not Bridged. The gain control on the back needs to be set to match whatever pre-amp you use, so this takes some research for proper setup.

That's a nice vintage turntable.

 

[TLS Guy]

So are all the amps trash or are the other two amps worth anything?

You said you were going to assemble a set up with it, not seel it. No, the items are not worthless. You can sell the Crown IC 150, just sell then untested, parts or repair. Then you won't get a bad seller rep, or get yourself in trouble in eBay. If you sell it that way, it is much more likely that the amps will be bought by someone who knows what they are doing, and at least test them on the bench. It is quite likely they will add at least a "crowbar" protection circuit, which is not that difficult, to avert a catastrophe.

 

[Eppie]

You said you were going to assemble a set up with it, not seel it. No, the items are not worthless. You can sell the Crown IC 150, just sell then untested, parts or repair. Then you won't get a bad seller rep, or get yourself in trouble in eBay. If you sell it that way, it is much more likely that the amps will be bought by someone who knows what they are doing, and at least test them on the bench. It is quite likely they will add at least a "crowbar" protection circuit, which is not that difficult, to avert a catastrophe.

Just curious but would simple glass buss fuses offer protection in that case or would they be likely to burn out under normal use?

 

[TLS Guy]

Just curious but would simple glass buss fuses offer protection in that case or would they be likely to burn out under normal use?

Glass fuses do not blow quick enough.

 

[lovinthehd]

Any idea what your relative did with the gear at all? Wonder if he added the "crowbar" protection circuit....

What cartridge does the turntable have?

 

[jcrowde3]

He used to have a pair of 4312 floor standers as well as the 4312s he gave me. He somehow used all this to power all 4 speakers. I asked him what he would use to power the 4312s and he said the Hafler so I will probably do it that way when I get a preamp.

 

[lovinthehd]

Personally I wouldn't run all four off the Hafler in any case, impedance load just a bit too much for that amp I think let alone acoustic issues from running two pair in 2ch mode. In the early 80s I bought the matching Hafler pre-amp kit but used a more powerful amp. I also have a pair of 4311Bs I picked up not long ago.

Do you know which particular 4312 model you have? https://www.hifiengine.com/manual_library/jbl/4312.shtml

 

[jcrowde3]

Personally I wouldn't run all four off the Hafler in any case, impedance load just a bit too much for that amp I think let alone acoustic issues from running two pair in 2ch mode. In the early 80s I bought the matching Hafler pre-amp kit but used a more powerful amp. I also have a pair of 4311Bs I picked up not long ago.

Do you know which particular 4312 model you have? https://www.hifiengine.com/manual_library/jbl/4312.shtml

It just says JBL Model 4312 Control Monitor on the front.

 

[jcrowde3]

The Onkyo 494 isn't suitable for use as a pre-amp as that Onkyo only has pre-outs for a sub (you'd want at least L/R speaker pre-outs generally to use an external amp). The avr may be more friendly to using with video, tho, and you could just use a phono pre-amp (aka phono stage) for the tt into one of the avr's line inputs. ART makes some good affordable phono pre-amps too.

Hi, I was looking at the the Onkyo 494 last night and it has a Zone B pre out (L/R) can that not be used as a pre amp?

 

[Eppie]

Hi, I was looking at the the Onkyo 494 last night and it has a Zone B pre out (L/R) can that not be used as a pre amp?

Yes, I checked the manual and the Zone B pre-out can be used as a pre-amp to feed one of your amps.

 

[jcrowde3]

Yes, I checked the manual and the Zone B pre-out can be used as a pre-amp to feed one of your amps.

Thanks!

 

[Eppie]

Thanks!

Guess I should add a caveat. Amplifiers have different input sensitivities. The Crown 460 is adjustable but the Hafler is not. The Hafler is rated at 1.55V on the input to generate 115W. The Onkyo manual says the Zone-B RCA out is rated at 1V, so you won't get the full 115W out of the Hafler, but at least you should not be able to overdrive it and damage the amp. Probably best not to push that old amp to full power any way.

 

[lovinthehd]

Hi, I was looking at the the Onkyo 494 last night and it has a Zone B pre out (L/R) can that not be used as a pre amp?

I missed that but zones sometimes also restrict some digital sources, too. I'd just prefer an avr with a set of pre-outs on the main zone, but this could work especially since you already have the avr.

 

[lovinthehd]

Guess I should add a caveat. Amplifiers have different input sensitivities. The Crown 460 is adjustable but the Hafler is not. The Hafler is rated at 1.55V on the input to generate 115W. The Onkyo manual says the Zone-B RCA out is rated at 1V, so you won't get the full 115W out of the Hafler, but at least you should not be able to overdrive it and damage the amp. Probably best not to push that old amp to full power any way.

Some of the Onkyos even with the nominal spec of 1V could output higher than that, tho.....