Dennis Had Inspire Amps

[Bentan]

Originally Posted by straitwire

Hey Bentan, Dennis designs for about 12 to 13 db gain on all the Inspire preamplifiers.

Would you know how many db gain 1.4V (I just checked the manual) on my MA7200 translates to? Thanks again!

[Bombadil]

Originally Posted by Bentan

Would you know how many db gain 1.4V (I just checked the manual) on my MA7200 translates to? Thanks again!

The McIntosh MA7200 integrated amp's preamp output produces a maximum of 8V. The 1.4V spec is stating how much voltage is needed by the amplifier section to produce its full rated 200 wpc. I.e. the amp's input sensitivity specification.

8V is more than enough to drive any power amplifier to full power / clipping. That is unless the source's output is very low. Say playing a CD which was recorded with extremely low volume levels.

8V is a pretty common specification, many preamps' output voltage is in that neighborhood. Some do go higher, I have a Conrad-Johnson which has a maximum output of 17V, but I'm sure I never get it anywhere near that.

[Bentan]

Originally Posted by Bombadil

The McIntosh MA7200 integrated amp's preamp output produces a maximum of 8V. The 1.4V spec is stating how much voltage is needed by the amplifier section to produce its full rated 200 wpc. I.e. the amp's input sensitivity specification.

8V is more than enough to drive any power amplifier to full power / clipping. That is unless the source's output is very low. Say playing a CD which was recorded with extremely low volume levels.

8V is a pretty common specification, many preamps' output voltage is in that neighborhood. Some do go higher, I have a Conrad-Johnson which has a maximum output of 17V, but I'm sure I never get it anywhere near that.

Thank you for explaining.

I’ve tube rolled the KT170, KT88, KT77 and 7581s. I have to say the KT77s with the 5AR4 are my favorite. The 88s have a bit more power. Really satisfied.

[AMammal]

Man, some really cool updates! Thanks for sharing all this everyone! Those 300B amps are sure to command quite a bit of demand!

[joel_hifi]

Happy new owner here of a Fire-Bottle in red coating, fitted with Gold Lion KT88s, GE NOS 6SN7 GTB, Sovtek 5AR4

I'll be reading through the 6000+ thread but if I may dare the shortcut I would greatly appreciate your advices for alternative rectifier tubes, thanks

[Bombadil]

I own 5 different 5AR4 / GZ34 rectifiers. In both my SE HO and my PSE amp, all five sound exactly the same to my ears.

It is changing the 6SN7 tube where I hear differences.

[Bentan]

Originally Posted by joel_hifi

Happy new owner here of a Fire-Bottle in red coating, fitted with Gold Lion KT88s, GE NOS 6SN7 GTB, Sovtek 5AR4

I'll be reading through the 6000+ thread but if I may dare the shortcut I would greatly appreciate your advices for alternative rectifier tubes, thanks

Congrats ! I’m using the Goldlion 5AR4 . Doesn’t sound much different to be honest. And also the 5U4G with the 7581A. I have the 5Y3 but I’ve got no PT to match them with yet.

[joel_hifi]

Bombadil, Bentan, many thanks for your kind feedback

Rectifier tube - well noted, so no much difference between various 5AR4/5U4/5Y3... would you say it's also true/same for 274B?

Input driver tube - it came with the GE NOS 6SN7 GTB, is there any other tube that would possibly better that one?

Thanks!

[Isaacc7]

Got my KT88 fire bottle middle of last year and have had a blast with it. Came with a GE 6sn7, Sovtek 5ar4, and a pair of PSVane KT88 Treasure tubes. Thought it sounded great but I had to try other tubes of course!

I own a variety of 6sn7 and 6sl7 tubes but they are buried in storage a ways away. Had a friend send me a spare GE 6sl7 he had. Also bought a new 5u4G. Tried different combos of those tubes along with 807, new 7581a, el34, 6v6, and GL KT66. Ended back at the combo that came with the amp lol!

These KT88s have a bell like clarity that is addictive. All of the other combos sounded veiled to me. Now I'm hearing about the big Tung Sol tubes and I'm curious about those. It's one thing for internet randos to praise a tube but when the guy that designed your amp extolls their virtues I take notice! So what are people's experiences going from the KT88 to the 120,150, or 170?

I have always liked Sylvania 6sn7 and 6sl7 tubes in previous amps I have had so I am looking forward to hearing them in this amp too. I got some 7n7 tubes and am waiting for the adapters to come in.

I've had fun reading 200+ posts in this thread! I met Dennis 25 or so years ago at a get together at Deja Vu audio when he was demonstrating his Cary 805 amps. Had always wanted to own one of his SE amps and now I do! Happy days!

[Bentan]

Originally Posted by joel_hifi

Bombadil, Bentan, many thanks for your kind feedback

Rectifier tube - well noted, so no much difference between various 5AR4/5U4/5Y3... would you say it's also true/same for 274B?

Input driver tube - it came with the GE NOS 6SN7 GTB, is there any other tube that would possibly better that one?

Thanks!

Hi Joel_hifi, to be clear , there are differences between the different types of rectifier tubes because they have different voltage drop. From what I know, for instance, the 7581A should not be used with the 5AR4. I’ll leave the explanation to the more experienced and knowledgeable guys around here. What I meant was that there are no audible differences to me across different brands of the SAME rectifier tube types.

I have a bunch of 6SN7 but I haven’t got around to rolling them yet.