Dennis Had Inspire Amps

[BearCityUSA]

Originally Posted by trackpad

I'm using a PowerVar Power Conditioner Model ABC1200-11. The rest of my system is dead quiet. I'm going to experiment and unplug as many potential sources and see what happens.

I'm taking a different tact. Eliminate the possible external sources by taking both Pre and KT to the office today. Heck, I even have a different power company there. If the hum is still present then I figure it may be a wiring incompatibility between the two.

[lsquaredb]

Is the humming preamp connected to the tv or something connected to the tv? I had a hum problem that was caused by a ground loop involving the tv cable. I solved it by using an optical digital cable between TV or the Apple TV and the DAC. This electrically isolated the TV equipment from the stereo equipment and broke the ground loop.

If the preamp is an LP27a, it might just be a bad tube causing the hum. I had this problem with balloon 27's, but eventually found a couple that didn't hum.

[Comzee]

One of the reasons I love this amp, even tho no combo might be "the best" it's refreshing to switch it up every now and then, feels like a new amp every time

Running 807 + 6su7 + 596 right now, quite captivating.

[FloridaBoy]

Originally Posted by Comzee

One of the reasons I love this amp, even tho no combo might be "the best" it's refreshing to switch it up every now and then, feels like a new amp every time

Running 807 + 6su7 + 596 right now, quite captivating.

Inspire flavor of the month.

[Wgarcia]

Forgive me if this was addressed in one of the previous 4,317 posts, but I wondered what rectifier tube (if any) is suggested when using KT150s in my 12/16 build Fire Bottle. Incidentally, the amp arrived (bought allegedly barely used a few weeks ago) with a JJ 5Y3S, GL KT88s, and an Amperex 6SN7GTB. Dennis Had said in an Ebay message that I'm now part of the family (he also said KT150s would "work fine") and I now "need" an LP3-A preamp…I responded asking about those and he hasn't responded, but it's been only 3 weeks…he's likely building headphone amps after a recent review…or something. Also, this is the best sounding amp I've owned in over 5 decades of caring about such things.

[Masterlu]

Wgarcia... Welcome to AA!

[Rosco65]

Originally Posted by Wgarcia

Forgive me if this was addressed in one of the previous 4,317 posts, but I wondered what rectifier tube (if any) is suggested when using KT150s in my 12/16 build Fire Bottle. Incidentally, the amp arrived (bought allegedly barely used a few weeks ago) with a JJ 5Y3S, GL KT88s, and an Amperex 6SN7GTB. Dennis Had said in an Ebay message that I'm now part of the family (he also said KT150s would "work fine") and I now "need" an LP3-A preamp…I responded asking about those and he hasn't responded, but it's been only 3 weeks…he's likely building headphone amps after a recent review…or something. Also, this is the best sounding amp I've owned in over 5 decades of caring about such things.

If your amp has the IIPS mod from the Toy Factory it doesn't matter what rectifier you use. If you have an older model it will be more sensitive to rectifier choice. Just about any pentode or tetrode from an EL84 (with adapter) to a KT150 will work.

It doesn't "need" an LP-3a, but it benefits from the gain.

[Bombadil]

I'm surprised that an Inspire amp would ship with KT150 output tubes and a 5Y3S rectifier. The 5Y3 series are low power rectifiers. I usually use those with 6V6 tubes to reduce the demands upon them. I would like to have a pair of KT150s to try in my amp as those would maximize power output. I would pair my Genalex GZ34 rectifier with them to maximize their output. Very low voltage drop from a GZ34/5AR4. That is, unless I had the IIPS mod.

[Rosco65]

Originally Posted by Bombadil

I'm surprised that an Inspire amp would ship with KT150 output tubes and a 5Y3S rectifier. The 5Y3 series are low power rectifiers. I usually use those with 6V6 tubes to reduce the demands upon them. I would like to have a pair of KT150s to try in my amp as those would maximize power output. I would pair my Genalex GZ34 rectifier with them to maximize their output. Very low voltage drop from a GZ34/5AR4. That is, unless I had the IIPS mod.

If the amp is from late 2016 it likely has the IIPS mod. In that case, the rectifier has zero effect on B+ or output power. The rectifier is acting as a secondary rectifier/buffer for the regulated PS.

Whether a different rectifier in this use makes a difference is a matter for a different discussion.

[Comzee]

Originally Posted by Bombadil

Very low voltage drop from a GZ34/5AR4. That is, unless I had the IIPS mod.

I have the IIPS and I've rolled many rectifiers (b4 and after upgrade). In either scenario I found rectifiers still give a massive difference in sound.

With that said, I wholeheartedly agree with gz34, it's the only rectifier I've tried with my kt150 that can somewhat flesh them out. Since the Fire-Bottle was never directly intended for KT150, I'm not sure even with gz34 it's really pushing them to full potential.

Anything other than gz34 really kills the kt150 (imo) (ymmv).