2 Bus LT Warning!!!!!!!!

bluemuse · 24th June 2004, 01:38 AM

I should know better and I'm sure that I'm going to get slammed for this but........

After reading the post on the Dangerous 2 Bus I decided to order the LT1357 chips and give them a try. So I open up the 2 Buss Light and reach for the only socketed chips in there, swap them out, put the lid back on and get ready for the magic. Only there is no sound coming out of my speakers.

I think, Christ did I put them in backwards? Back in I go. The chips are in the right way around, but they are very hot.

Are these compatible chips? I measure what pins the power is coming in on.
Pins 5 and 6, which seems odd to me.
This is where I start to worry.

To the internet to look up specs. Well the socketed chips in a 2bus light are BB DRV134PA and sure enough power is on pins 5 and 6. But the power on the LT1357 is 4 and 7.

Time to re-read the post about chip swapping.

Here were I feel like an ass. I was supposed to swap the op134s, which in a 2 buss light are surface mounted.

Ok, swap the DRC 134PAs back, put in back in the rack and power up. Hopefully get something done tonight.

Bad news, distortion everywhere. I go back in and discover that I've blown up the power supply!!!! +15/-35V No Good.

I called Dangerous Music and spoke to Bob who couldn't have been nicer.
He explained, as did Eveanna regarding Manley gear, that the components where chosen for a reason. And that you could swap stuff around if you wanted but that they didn't cut corners when specing out the parts.

I'm not choosing sides here I just want to pass along my experience with this.

Ernie

Chris Muth · 24th June 2004, 04:33 AM

Hi Ernie,

Sorry you had a bummer with the output drivers. Yeah, the juice pins are different than single 8 pin op amps! I've tried the Linear Technologies chips in 2Bus and didn't like them for the app as much as the BB stuff. THe BB 604 is a bit too fast in this circuit also. I think it sounds harsh. Funny thing about voicing circuits is that the numbers on a spec sheet don't say much about how a particular device will sound in the circuit. The chip set that I picked seems to me (and many others) to have just the right flavor for this box.

Bring your LT in and we'll check it out to see what happened...

cu
cm

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24th June 2004, 01:38 AM	#1
bluemuse Gear interested Join Date: Apr 2004 Posts: 15	2 Bus LT Warning!!!!!!!! I should know better and I'm sure that I'm going to get slammed for this but........ After reading the post on the Dangerous 2 Bus I decided to order the LT1357 chips and give them a try. So I open up the 2 Buss Light and reach for the only socketed chips in there, swap them out, put the lid back on and get ready for the magic. Only there is no sound coming out of my speakers. I think, Christ did I put them in backwards? Back in I go. The chips are in the right way around, but they are very hot. Are these compatible chips? I measure what pins the power is coming in on. Pins 5 and 6, which seems odd to me. This is where I start to worry. To the internet to look up specs. Well the socketed chips in a 2bus light are BB DRV134PA and sure enough power is on pins 5 and 6. But the power on the LT1357 is 4 and 7. Time to re-read the post about chip swapping. Here were I feel like an ass. I was supposed to swap the op134s, which in a 2 buss light are surface mounted. Ok, swap the DRC 134PAs back, put in back in the rack and power up. Hopefully get something done tonight. Bad news, distortion everywhere. I go back in and discover that I've blown up the power supply!!!! +15/-35V No Good. I called Dangerous Music and spoke to Bob who couldn't have been nicer. He explained, as did Eveanna regarding Manley gear, that the components where chosen for a reason. And that you could swap stuff around if you wanted but that they didn't cut corners when specing out the parts. I'm not choosing sides here I just want to pass along my experience with this. Ernie

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24th June 2004, 04:33 AM	#2
Chris Muth Gear interested Join Date: Jun 2004 Location: NYC Posts: 24	Hi Ernie, Sorry you had a bummer with the output drivers. Yeah, the juice pins are different than single 8 pin op amps! I've tried the Linear Technologies chips in 2Bus and didn't like them for the app as much as the BB stuff. THe BB 604 is a bit too fast in this circuit also. I think it sounds harsh. Funny thing about voicing circuits is that the numbers on a spec sheet don't say much about how a particular device will sound in the circuit. The chip set that I picked seems to me (and many others) to have just the right flavor for this box. Bring your LT in and we'll check it out to see what happened... cu cm