Ordered a Schiit Aegir (single) for my Cornwalls....

[Shakeydeal]

I don't think you are going to discern any advantages (or not) of monoblocks by using two different amps with (likely) wildly different gain structures. Just my two cents......

[costerdock]

53 minutes ago, Shakeydeal said:

I don't think you are going to discern any advantages (or not) of monoblocks by using two different amps with (likely) wildly different gain structures. Just my two cents......

Thanks - I think you are probably right and I certainly don't want to make the same mistake twice buying monoblocks again.  I would have been much better off with an ST70 - especially now dealing with all the issues that M125's bring.

[Shakeydeal]

I've always thought that it's the design of the amp that matters more than separating channels into two chassis'. I've had stereo amps sound better than monos and vice versa. All things being equal, monoblocks would probably sound better. But hardly ever are all things equal.

[costerdock]

1 hour ago, rjw1678 said:

I got my Schiit Aegir in November. I use it with a pair of 1996 LaScala's. It sounds amazing. I have attached a chart that PWK put together on amplifier power and sound level, the chart also includes Cornwalls.

 

Thanks that is wonderful to hear.   I have a good baseline with the M125s so we will see how this works out.

 

Thanks again!

[captainbeefheart]

Monoblocks are great for people that want to closely couple the amp to speaker with as little speaker wire in the way as possible. For tube amps of higher power levels and even solid state amps running deep Class A they can cut down the weight of what you need to carry, high powered tube stereo's get very heavy. Another pro is reducing cross talk, especially with Class AB amps, one channel might be in Class B while the other isn't but both channels will suffer the response of the power supply to the increased load demand. There are other benefits for mono amps but for most of us, especially if we do not require high power amplifiers a stereo or integrated amplifier is just easier and good enough for our needs.

 

If you listen to mainly vinyl records the cross talk is already plain awful. Huge damping factor isn't going to be necessary for most so a stereo unit with average speaker wire lengths are just fine for performance if sized correctly.

 

 

[grendel23]

20 hours ago, captainbeefheart said:

1N4007 is around 15pF, this causes a resonance every current pulse that can have a large overshoot and ringing on top of the current waveform, it's just more harmonics and junk the power supply caps need to deal with and filter out.

I have a pair of M125s and am using the Weber solid state rectifiers recommended by Bob Latino. Do you think these are a good choice, or would it be better to use tubes?

[costerdock]

13 minutes ago, grendel23 said:

I have a pair of M125s and am using the Weber solid state rectifiers recommended by Bob Latino. Do you think these are a good choice, or would it be better to use tubes?

I used the webers back in 2011 (W68) as recommended back when I built the amp - until one burnt up.  But back then the bias was set at 1.2 amps - way too high - and VTA came down with a setting of 1.0.  I was told to use Mullards as they are "indistructable" so I bought a couple WZ37s and used those for years - I'm hoping my last meltdown didn't destroy them as they are very $$$.

 

The only one to run SS is the WS1 - but that requires a slow tube warmup module - otherwise the voltage will come on too fast and hurt the tubes.   That is something I have to adopt.  Tubes just get beaten up with these amps - they are just too much over the top.  I'm a frustrated M125 owner - you will hear of the others in my AK thread - all with similar stories.

 

I had good luck with glass when I ran two output tube config with a bias setting of .500 mA.  I've had the best luck with that setup - @ 5 years of stability.   The ST120 and M125s - I've heard from very good sources that they should really have two rectifiers.

 

[Curious_George]

20 hours ago, captainbeefheart said:

Some people get lucky using other diodes (instead of 1N4007's) with less capacitance, they are typically called fast recovery diodes, although we do not need fast recovery for a 120Hz current pulse it will have lower capacitance changing the resonance frequency and amplitude to a more acceptable amount.

I have used the 1N series forever for audio projects and never had any issues. I compared 4007's to the fast recovery in an audio circuit and there was no difference in listening or measuements.

 

Perhaps in some "audio" circuits people actually had an improvement (measureable) noise wise, but I have not. 

[captainbeefheart]

2 hours ago, Curious_George said:

I have used the 1N series forever for audio projects and never had any issues. I compared 4007's to the fast recovery in an audio circuit and there was no difference in listening or measuements.

 

Perhaps in some "audio" circuits people actually had an improvement (measureable) noise wise, but I have not. 

 

I should have been more elaborate, we aren't dealing with something that will change the sound of the amplifier. This is for me is an exercise to reduce or eliminate as much RFI from the amp as possible. Yes the power supply should filter most of it out but electrolytic capacitors typically have higher ESR with RF and so it's better to just have it not there to begin with.

 

[Curious_George]

3 minutes ago, captainbeefheart said:

Electrolytic capacitors typically have higher ESR with RF and so it's better to just have it not there to begin with.

I concur. I was just relating my observations. 

[captainbeefheart]

3 hours ago, grendel23 said:

I have a pair of M125s and am using the Weber solid state rectifiers recommended by Bob Latino. Do you think these are a good choice, or would it be better to use tubes?

 

The only way to tell is to actually have the amplifier in front of me on a test bench to see if there is ringing with the Weber SS rectifiers in that specific amplifier. With those amps I would personally think a SS power supply would be best.

 

Contrary to what myths that have been floating around it will not hurt your tubes to have B+ on the plates and the heaters cold. This was only ever an issue with say transmitting tubes running at several thousand volts and still depends on the type of filament/cathode materials. What's worse for tubes is if you leave the heaters running and there be no current flowing or no plate voltage, that can possibly poison the cathode but still usually not an issue but I have seen that, I have never seen cathode stripping from an amp with voltage on the plates for a few seconds while the heaters are warming up. The only concern is your power supply voltage rating, with no heaters warmed up there is no load, B+ is maximum potential in this time period. Amps should be made for worst case scenario and no load just in case somebody power up the amp with zero tubes plugged in. If the power supply voltage rating is fine handling a SS rectifier then go for it.

[captainbeefheart]

7 minutes ago, Curious_George said:

I concur. I was just relating my observations. 

 

I completely understand, I just wanted people not freak out and lose sleep over using SS rectifiers and if their power supplies are ringing like a bell. It was good for me to chime back in anyway and just let people know for me I just feel the power supply is cleaner without the bursts of RF noise being created regardless if it's something that will be audible through the speakers, it's just a purer cleaner system if you will.

[captainbeefheart]

I'll be transparent, the reason I like tube rectifiers for low power Class A amps is because I'm lazy and I know the supply will be well damped, heck the tube still being in the circuit for some of the people adding the silicon diodes in series with the 5AR4 will be fine due to the tube's plate resistance is still in the circuit. But ya I don't think there is even a sonic difference between tube and SS with most of the low powered Class A circuits. I'm just obsessive compulsive about things so if to be cheap or save space use silicon diode rectifiers with a Class A amp or any amp for that matter I'll end up checking for ringing/overshoot and add a snubber if needed.

 

I should keep my postulating to myself sometimes, I was hypothesizing about why his filter caps went bad shortly after the mod was possibly due to increased RF currents through the electrolytics where the ESR will be highest and add more heat. It's just a theory.

 

Another theory could be the heat from soldering in the diodes traveled from the wire to the filter caps and sped up their demise. Or it was just a coincidence.

[costerdock]

29 minutes ago, captainbeefheart said:

 

The only way to tell is to actually have the amplifier in front of me on a test bench to see if there is ringing with the Weber SS rectifiers in that specific amplifier. With those amps I would personally think a SS power supply would be best.

 

Contrary to what myths that have been floating around it will not hurt your tubes to have B+ on the plates and the heaters cold. This was only ever an issue with say transmitting tubes running at several thousand volts and still depends on the type of filament/cathode materials. What's worse for tubes is if you leave the heaters running and there be no current flowing or no plate voltage, that can possibly poison the cathode but still usually not an issue but I have seen that, I have never seen cathode stripping from an amp with voltage on the plates for a few seconds while the heaters are warming up. The only concern is your power supply voltage rating, with no heaters warmed up there is no load, B+ is maximum potential in this time period. Amps should be made for worst case scenario and no load just in case somebody power up the amp with zero tubes plugged in. If the power supply voltage rating is fine handling a SS rectifier then go for it.

Whether it is a myth or not - I'm adopting the delay board:

 

- ($)Buy RUBLI delay board (http://rubli.net/HT_delay/)

 

I'm doing this because - my amps have killed enough tubes and people that seem to know what they are talking about (VTA folks - Bob, Roy) - non VTA folks - all say - you can't run the SS WS1 w/o a time delay module.

 

As a consumer I have to listen to what I feel are experts - not to mention my own experiences with these amps blowing rectifiers, and output tubes - I'll do anything to take it easy on those tubes.

 

 

That is - if I decide to put any more effort into these amps.

 

[Curious_George]

1 hour ago, costerdock said:

As a consumer I have to listen to what I feel are experts...

 

What is an expert? Someone who knows one more thing than you!

 

I used to have an associate say that all the time. It was funny in most business circumstances. 

[Curious_George]

1 hour ago, captainbeefheart said:

Contrary to what myths that have been floating around it will not hurt your tubes to have B+ on the plates and the heaters cold. This was only ever an issue with say transmitting tubes running at several thousand volts and still depends on the type of filament/cathode materials. What's worse for tubes is if you leave the heaters running and there be no current flowing or no plate voltage, that can possibly poison the cathode but still usually not an issue but I have seen that, I have never seen cathode stripping from an amp with voltage on the plates for a few seconds while the heaters are warming up. The only concern is your power supply voltage rating, with no heaters warmed up there is no load, B+ is maximum potential in this time period. Amps should be made for worst case scenario and no load just in case somebody power up the amp with zero tubes plugged in. If the power supply voltage rating is fine handling a SS rectifier then go for it.

Yep, Cathode Stripping, biggest urban myth there ever was and people are still defending it today on the Internet. 

 

It's like my other favorite urban myth, putting a vehicle lead-acid battery on your concrete garage floor. A lot of people believe there is some mystical property in the concrete that will suck all the energy out of that battery. However, if you put the battery on a 2x4 propped up off the floor, the battery will not get drained. 

 

 

[CWelsh]

38 minutes ago, Curious_George said:

What is an expert? Someone who knows one more thing than you!

 

I used to have an associate say that all the time. It was funny in most business circumstances. 

I spent a large chunk of my career working as a consultant.  Our definition of an "expert" was, anyone more than 35 miles from home and carrying a briefcase (or, backpack for tech companies).

[Area 51]

8 hours ago, captainbeefheart said:

Monoblocks are great for people that want to closely couple the amp to speaker with as little speaker wire in the way as possible.

Super! This raises a couple of issues I have been wondering about for a while. May I preface my question(s) with an apology if my ignorance gets in the way of anyone's genuine learning. I'm still new at this. Captain, I think I understand "as little speaker wire in the way as possible." Is it safe to assume that means longer interconnects are preferable to longer speaker wires? Can we regard that as a general rule?

I have just received my 2nd Aegir and would like to experiment with them as mono blocks powering my Cornwalls and later try them out with my recently acquired Belles. Should I locate my newest Aegir and it's twin as close as possible to each of the Cornwalls and live with longer interconnects from my Freya+ pre amp?

I also wanted to experiment with a pair of low power tube amps as well. Schiit offers the option to use the Aegirs in mono mode. My cheap tube amps are twins but do not offer the mono option. They are stereo amplifiers. Can I use them as (mono?) blocks with my Cornwall IIIs? If each amp is powering one speaker does the "mono block" terminology go away and does it take any dual amplifiers benefits with it or would this be just another form of bi amping?

Thanks in advance for the lesson.

I appreciate any input. 

 

 

[costerdock]

10 minutes ago, Area 51 said:

Super! This raises a couple of issues I have been wondering about for a while. May I preface my question(s) with an apology if my ignorance gets in the way of anyone's genuine learning. I'm still new at this. Captain, I think I understand "as little speaker wire in the way as possible." Is it safe to assume that means longer interconnects are preferable to longer speaker wires? Can we regard that as a general rule?

I have just received my 2nd Aegir and would like to experiment with them as mono blocks powering my Cornwalls and later try them out with my recently acquired Belles. Should I locate my newest Aegir and it's twin as close as possible to each of the Cornwalls and live with longer interconnects from my Freya+ pre amp?

I also wanted to experiment with a pair of low power tube amps as well. Schiit offers the option to use the Aegirs in mono mode. My cheap tube amps are twins but do not offer the mono option. They are stereo amplifiers. Can I use them as (mono?) blocks with my Cornwall IIIs? If each amp is powering one speaker does the "mono block" terminology go away and does it take any dual amplifiers benefits with it or would this be just another form of bi amping?

Thanks in advance for the lesson.

I appreciate any input. 

 

 

 

I've run my tube monoblocks very close to the speakers w extremely short speaker cables and long interconnects - and I've also run the amps on my rack with very long speaker cables and short interconnects.

 

I could detect no noticeable difference.   As such I have no preference - I'm OK with either setup.

[costerdock]

15 minutes ago, Area 51 said:

Super! This raises a couple of issues I have been wondering about for a while. May I preface my question(s) with an apology if my ignorance gets in the way of anyone's genuine learning. I'm still new at this. Captain, I think I understand "as little speaker wire in the way as possible." Is it safe to assume that means longer interconnects are preferable to longer speaker wires? Can we regard that as a general rule?

I have just received my 2nd Aegir and would like to experiment with them as mono blocks powering my Cornwalls and later try them out with my recently acquired Belles. Should I locate my newest Aegir and it's twin as close as possible to each of the Cornwalls and live with longer interconnects from my Freya+ pre amp?

I also wanted to experiment with a pair of low power tube amps as well. Schiit offers the option to use the Aegirs in mono mode. My cheap tube amps are twins but do not offer the mono option. They are stereo amplifiers. Can I use them as (mono?) blocks with my Cornwall IIIs? If each amp is powering one speaker does the "mono block" terminology go away and does it take any dual amplifiers benefits with it or would this be just another form of bi amping?

Thanks in advance for the lesson.

I appreciate any input. 

 

 

It is awesome that you liked the Aegir so much that you got another - that is a great indication to me that these are nice amps.

 

Thanks again for your comment.