Dennis Had Inspire Amps

[pstrisik]

Originally Posted by nhparrot

Rectifier Question, which will drive the output tubes harder and why?

Tube -------- Fvolt - Famp - Vdrop - MaxPmA - MaxPv
5AR4/GZ34 -- 5.0 --- 1.9 --- 17 ---- 250 ----- 450
5Z4 --------- 5.0 --- 2.0 --- 20 ---- 125 ----- 350

Is it the voltage drop (Vdrop) or the plate voltage/output current (MaxPV/MaxPmA) to be concerned with?

Good question! I would like to understand those specs as well. I'm currently using a Mullard 5V4G:

Tube -------- Fvolt - Famp - Vdrop - MaxPmA - MaxPv
5V4-G/GA ----- 5.0 --- 2.0 --- 25 ---- 175 ---- 375

The author of the rectifier table did quite a bit of writing below the table itself. It looks to me like the two "Max" specs are capabilities, so higher is better to handle more situations. Famp is the heater current - I'm not sure of the implications of higher or lower. The author expresses the most caution about low voltage drop. It reads like the voltage drop allows for flexibility in current handling. With low voltage drop, the voltage doesn't decrease as much with added demand. Hence the "surge" risk.

A popular tube still being made is the 5AR4/GZ34. This is basically
an improved redesigned 5U4/5Y3 tube. It has a 1.9amp heater and plate
voltage and current similar to the 5U4 so it can be used in either
circuit. However it has a much lower voltage drop so care should
be used to be sure that the circuit can handle the extra current
surge. This tube is usually best used in a circuit that is designed
to handle the low voltage drop.

This is interpretation from me, who knows not a lot about tube design, so I am open to correction to any or all of the above!!

[nhparrot]

Originally Posted by pstrisik

Good question! I would like to understand those specs as well. I'm currently using a Mullard 5V4G:

Tube -------- Fvolt - Famp - Vdrop - MaxPmA - MaxPv
5V4-G/GA ----- 5.0 --- 2.0 --- 25 ---- 175 ---- 375

Peter, couple questions. What tube complement are you using with the 5V4G and how did those Brimar 6V6's you tried compared to 6V6GT's like the Popes?

Thanks
Glenn

[pstrisik]

Originally Posted by nhparrot

Peter, couple questions. What tube complement are you using with the 5V4G and how did those Brimar 6V6's you tried compared to 6V6GT's like the Popes?

Thanks
Glenn

Glenn..... I'm currently using a Voskhod 6N23P driver and Visseaux 6V6 power tubes with the 5V4G. The Omega Super Alnico Monitors have more hi freq extension than the previous Omegas that I had and my tube preferences have shifted around.

The Brimar 6V6's weren't anything special when I tried them. I can't recall if I've tried them with these speakers though, so I will again and post back.

I saw a NOS quad of Visseaux 6V6's go on ebay the other day. I was curious if anyone here had snagged them. They don't come up much any more. The Popes sound a bit soft to me these days.

[BearCityUSA]

Originally Posted by pstrisik

Good question! I would like to understand those specs as well. I'm currently using a Mullard 5V4G: Tube -------- Fvolt - Famp - Vdrop - MaxPmA - MaxPv 5V4-G/GA ----- 5.0 --- 2.0 --- 25 ---- 175 ---- 375 The author of the rectifier table did quite a bit of writing below the table itself. It looks to me like the two "Max" specs are capabilities, so higher is better to handle more situations. Famp is the heater current - I'm not sure of the implications of higher or lower. The author expresses the most caution about low voltage drop. It reads like the voltage drop allows for flexibility in current handling. With low voltage drop, the voltage doesn't decrease as much with added demand. Hence the "surge" risk. This is interpretation from me, who knows not a lot about tube design, so I am open to correction to any or all of the above!!

This is an interesting discussion. With Ohms Law (V=IR), voltage has a direct inverse relationship to current. If you double one you half the other if resistance remains constant. With a low voltage drop (240-17 = 223 volts) vs higher voltage drop (240-25=215) the former would draw less current than the latter. It seems a low v-drop rectifier would provide a reduced current demand throughout the circuit. Sorry if this is all so elemental but I had not really thought about all this before. What this all means for sound I have no idea and like you guys I hope someone else here can explain all this in laymen's terms so I can understand it. Cool topic,... Oh and Merry Christmas!

[pstrisik]

@Glenn,

Well, the Brimar 6V6ST pair is doing quite well this listen. I'm going to leave them in for a while and see where it goes. Most noticeable is a more open and pleasing upper freq. range.

And they look pretty damn good!

[JWH]

Originally Posted by FloridaBoy

Audio Research
Product Type
Amplifier
Product Name
Audio Research VS115
Product Model
VS115
Technical Information
Minimum Frequency Response
20 Hz
Maximum Frequency Response
20 kHz
Total Harmonic Distortion THD
0.5%
Audio

RMS Output Power
120 W


Your amp has PLENTY of power it just may not be a good pairing with your speakers. What are you using for a preamp? There are some amp and speaker combinations that are just not optimal. That does not mean they are not excellent when paired with something else.

I'm using an Audio Research LS27. My current thinking is that I need to try a more efficient speaker to get the dynamics I'm looking for. Perhaps a Devore O93 or similar. Anyone here tried them?

[robert_kc]

Originally Posted by JWH

I'm using an Audio Research LS27. My current thinking is that I need to try a more efficient speaker to get the dynamics I'm looking for. Perhaps a Devore O93 or similar. Anyone here tried them?

I recently spent about 30 minutes auditioning the DeVore O/93 speakers with an Audio Research tube amp that was not equipped with tone controls. (I think it was a VSi60.) The O/93 speakers put out a lot of sound for a speaker with 2 drivers – however the high frequencies were too “bright” for my taste. The highs sounded “separate from” the music. My attention was constantly drawn to the high frequencies vs. the music. I never “got lost in the music” when listening to the DeVore O/93 - I was always aware that I was listening to speakers. (The fact that there were no grill covers may have contributed to my attention being constantly drawn to the high frequency drivers.)

I auditioned the O/93s listening to classical music. My reference is live classical music in a world-class symphony hall. Of course the DeVores have received some very favorable reviews, and you might like their sound.

I wonder if I might like the sound of one of the DeVore speakers if paired with the right amp – perhaps equipped with tone controls so that I could attenuate the treble. I’ve not heard the new DeVore “gibbon X”, and I’m curious about how it sounds.

Have you heard Klipsch RF-7 II speakers paired with a tube amp? As I mentioned earlier my Inspire SE Stereo Tube Amplifier HO (when equipped with 6DJ8, 5AR4, and GT-6L6-GE) delivers excellent sound quality with the Klipsch, with plenty of deep bass. With some amps I need tone controls to tame the RF-7’s high frequencies, but not with the Inspire SET amp. For big band music there is plenty of “punch” (i.e., dynamics). And for opera there is plenty of clean high frequency power to handle a soprano’s voice. (Actually I have one RF-7 on one channel, and an RF-7 II on the other. It’s a long story – I merged 2 separate mono systems into one stereo system.)

I have limited opportunities to audition speakers, because there are few retailers with demo rooms where I live. I wish that I could hear the Tannoy Kensington GR. Has anyone heard it?

[FloridaBoy]

Originally Posted by JWH

I'm using an Audio Research LS27. My current thinking is that I need to try a more efficient speaker to get the dynamics I'm looking for. Perhaps a Devore O93 or similar. Anyone here tried them?

There is something amiss. You have 120 watts RMS and that power should be able to drive darn near any speaker. Try to find an honest brick & mortar shop near you and go from there. Internet advice, in your situation, it the road to audio hell.

[FloridaBoy]

Originally Posted by robert_kc

I recently spent about 30 minutes auditioning the DeVore O/93 speakers with an Audio Research tube amp that was not equipped with tone controls. (I think it was a VSi60.) The O/93 speakers put out a lot of sound for a speaker with 2 drivers – however the high frequencies were too “bright” for my taste. The highs sounded “separate from” the music. My attention was constantly drawn to the high frequencies vs. the music. I never “got lost in the music” when listening to the DeVore O/93 - I was always aware that I was listening to speakers. (The fact that there were no grill covers may have contributed to my attention being constantly drawn to the high frequency drivers.)

I auditioned the O/93s listening to classical music. My reference is live classical music in a world-class symphony hall. Of course the DeVores have received some very favorable reviews, and you might like their sound.

I wonder if I might like the sound of one of the DeVore speakers if paired with the right amp – perhaps equipped with tone controls so that I could attenuate the treble. I’ve not heard the new DeVore “gibbon X”, and I’m curious about how it sounds.

Have you heard Klipsch RF-7 II speakers paired with a tube amp? As I mentioned earlier my Inspire SE Stereo Tube Amplifier HO (when equipped with 6DJ8, 5AR4, and GT-6L6-GE) delivers excellent sound quality with the Klipsch, with plenty of deep bass. With some amps I need tone controls to tame the RF-7’s high frequencies, but not with the Inspire SET amp. For big band music there is plenty of “punch” (i.e., dynamics). And for opera there is plenty of clean high frequency power to handle a soprano’s voice. (Actually I have one RF-7 on one channel, and an RF-7 II on the other. It’s a long story – I merged 2 separate mono systems into one stereo system.)

I have limited opportunities to audition speakers, because there are few retailers with demo rooms where I live. I wish that I could hear the Tannoy Kensington GR. Has anyone heard it?

Where do you live?

[FloridaBoy]

Originally Posted by pstrisik

Good question! I would like to understand those specs as well. I'm currently using a Mullard 5V4G:

Tube -------- Fvolt - Famp - Vdrop - MaxPmA - MaxPv
5V4-G/GA ----- 5.0 --- 2.0 --- 25 ---- 175 ---- 375

The author of the rectifier table did quite a bit of writing below the table itself. It looks to me like the two "Max" specs are capabilities, so higher is better to handle more situations. Famp is the heater current - I'm not sure of the implications of higher or lower. The author expresses the most caution about low voltage drop. It reads like the voltage drop allows for flexibility in current handling. With low voltage drop, the voltage doesn't decrease as much with added demand. Hence the "surge" risk.

This is interpretation from me, who knows not a lot about tube design, so I am open to correction to any or all of the above!!

The unknown variable is Dennis' auto bias implementation in the circuit. You may be over thinking this. The beauty of this gear is the simplicity. Just experiment with tubes until you hit the combo that does it for YOU in your room with your source(s).