[Roger A. Modjeski]

There is a lot going on here getting the new lab in order and I apologize that some things take longer than one might like. I have moved an enormous amount of equipment, parts and projects in the past half year and getting things organized to where they are easy to find has been quite a task that may go on for several more months.

However, I can't stop thinking of new designs and the prompting of members here. I have completed a phono preamp that has achieved such a high level of performance that I want to share it with you. Having played it for one of my foreign distributors, a few locals and another audiocircle member I can attest to it being "very quiet", "relaxed", "amplifies surface noise less" and is simply "listenable without being rolled off or colored".

Technically speaking I've been able to increase the gain of a pair of 6922s to 40 db from 36 and reduce input noise by 3 dB over the RM-5 phono stage. As most of you know, when it comes to noise I never stop till I have reached the theoretical limit of what the devices can provide. Those of you have tried some of the new popular phono stages know that this is often not the case with the preamps made by makers A, B and C.

In addition to reducing thermal noise (hiss or tube rush) I have reduced hum to zero by disconnecting from the power line. This preamp runs on a 12 volt rechargeable battery, has an excellent battery management system to keep the battery happy even if you forget and leave it on, and comes with a low noise charger that is almost as quiet allowing you to run it off line and recharge at the same time. A front panel switch lets you completely disconnect the charger and run on battery alone for the blackest background I have heard from a vinyl preamp. Via battery or charger. The battery ends the need for any line conditioning, fancy power cords or dedicated lines.

As always RIAA eq is passive and accurate to 0.5 dB, 2- RAM Super Low Noise (SLN) 6922s included. These are the best 6922s I've seen since I started using them in 1978. 12 volt, 7 AH battery $50. (plays over 10 hours per charge) With proper care battery life is over 3 years.

I am planning models with different features and even premium components priced from $1500 for the basic version to prices similar to what we see from makers A, B and C, but with far better performance.

As always, knowledge of your system and listening levels will get you the right equipment and save you money. The first units available (#1 below) have 40 db of gain and can be shipped with any loading you choose. Standard is 47 K ohms. This RIAA preamp is quiet enough to have noise below the surface noise of my best records even with my Denon 103 which is around 0.5 millivolts. If you have a line preamp to give another 10 dB of gain or you have sensitive speakers or you don't listen loud you may even be able to use a passive volume control as I do. With a high output cartridge of 2-5 mV you will have plenty of gain. Remember that 40 dB of phono gain takes a 5 mV cartridge to 500 mV which will drive most amplifiers to half of full output. Since most of us are using just a watt or two, there is plenty of gain in reserve.

As I am still developing the various embodiments of this new design I hope to post a poll as to features in the near future. For the meantime here are a few ideas I have had so far.

1. Basic unit for moving magnet cartridges in two small die cast, natural finish aluminum cases that mate directly to form one unit. The power supply is in one case, the phono preamp in the other for ultimate shielding. Tubes on the top with shields. Use the 12 volt battery of the type used in Back-up power supplies.  These batteries are now available at almost any electronics store. I can provide them also, its just that they are heavy to ship. Battery charger/eliminator and battery cable are supplied. Battery connects with simple push-on connectors, it couldn't be easier.

Here is how I mounted my modules. The battery is on its side in the box below the 2 modules. The battery can be anywhere. The two modules link together via 3 banana posts that go chassis to chassis.

http://s1085.photobucket.com/albums/j432/ramlabs/?albumview=slideshow

2. a head amp with front panel gain and loading (2 tubes)

3. a full featured MC/MM unit with front panel gain and loading (4 tubes)

Please post questions here.

Write ramtubes@gmail.com to order. Delivery 1 month after order.

[acresm22]

Roger, a question related to your SES series amps. Rumor has it (here on AC) that you're no longer producing them because the wooden chassis is no longer available. Is that true?

[Roger A. Modjeski]

Currently they are not available. I hope to make them available in the future if there is demand for them. I love mine.

[Roger A. Modjeski]

Please cast your vote for the phono preamp of your choice.

[Ericus Rex]

How about some pics of the options?

Regarding poll above.  I do think the days of the rack-mounted simple black-box component are long gone.  While sound is most important to all of us here the appearance of a component is now a close second...if solely for the reason that it makes the purchase easier to talk our spouses into (who are often not as enthusiastic about our expensive 'lifestyles').

[eeramos]

Agree!

[Roger A. Modjeski]

How about some pics of the options?

Regarding poll above.  I do think the days of the rack-mounted simple black-box component are long gone.  While sound is most important to all of us here the appearance of a component is now a close second...if solely for the reason that it makes the purchase easier to talk our spouses into (who are often not as enthusiastic about our expensive 'lifestyles').

I played this battery powered phono stage in its wood format (see pictures) for my Japanese distributor and his comment was that this kind of look does not go with most "decor". I would love to get the wives opinions on this as they are the arbiters of taste for many buyers. More and more I am wishing to express my artistic side in making nice looking pieces that sound good.

[GMuffley]

I vote for MC/MM capability (4 tubes); anodized natural aluminum finish; and, point to point wiring--no circuit boards.  Although no listed, a totem pole cathode follower (requiring 2 more 6922s) to buffer the phono stage output would be a nice option.  Fit it in a chassis the size of the RM-4 or RM-5 with cosmetics matching the RM-4 or RM-5.

[Roger A. Modjeski]

I vote for MC/MM capability (4 tubes); anodized natural aluminum finish; and, point to point wiring--no circuit boards.  Although no listed, a totem pole cathode follower (requiring 2 more 6922s) to buffer the phono stage output would be a nice option.  Fit it in a chassis the size of the RM-4 or RM-5 with cosmetics matching the RM-4 or RM-5.

Output impedance is less than 3K ohms, do you need a buffer for that?  If I added a volume control, then I would add a buffer after that.

[Clio09]

I would love to see a version with volume control and buffer to lower the output impedance. Balanced as well if possible. I'm sure that would add to the cost though.

[BobRex]

Keith Herron and a few SUT manufacturers have started suggesting, if not downright recommending input impedances above 47K.  Herron goes so far as to suggest an "infinite" load for MCs. (I don't know how Keith defines "infinite", but for arguments sake let's put it at > 1M).
Apparently SUTs are also happier with this higher load. 

Would it be possible to get that kind of load on the MM input?

On the aesthetics front, I'd prefer wood over plain aluminum.  Even black would be better than natural.

[Ericus Rex]

The new pics with the added upper wood level do make a lot more sense than the first few pics, aesthetically speaking.  Reminds me of some sort of Japanese box or miniature temple.  I do like the overall concept.  I would tweek the design by installing black acrylic (or the like) walls between the upper and middle shelves (morticed into the pillars) and have the switches installed in the walls and certainly do something to hide the tube sleeves; a cage or another smaller box on top.

I also have heard elsewhere that many cartridges benefit from above-47K loading.  Is it possible to do easy-access front or rear panel loading changes via a pot or DIP switches?  Various gain settings via easy access pot would be a plus too.  What comes to mind here is the versatility and ease of use of the Ray Samuels Nighthawk phono stage.

http://www.raysamuelsaudio.com/products/f-117

[Clio09]

My current phono stage has additional settings for 75k and 100k. I load my B&O MMC-2 moving iron cartridge at 100k. About 5 years ago I met Keith Herron at RMAF and he also mentioned his disdain for loading down MC cartridges. I see he caved to market perception though and offers a variety of loading options now.

[BobRex]

My current phono stage has additional settings for 75k and 100k. I load my B&O MMC-2 moving iron cartridge at 100k. About 5 years ago I met Keith Herron at RMAF and he also mentioned his disdain for loading down MC cartridges. I see he caved to market perception though and offers a variety of loading options now.

Actually, his moving coils stages have always had the ability to be loaded down.  You just had to solder the resistors in before.

[Roger A. Modjeski]

I would love to see a version with volume control and buffer to lower the output impedance. Balanced as well if possible. I'm sure that would add to the cost though.

I can do all that. But just why do you need that? There is no advantage in balancing a battery powered preamp or buffering 3K ohms unless you are running many many meters of cable to your neighbors house.

[Roger A. Modjeski]

The new pics with the added upper wood level do make a lot more sense than the first few pics, aesthetically speaking.  Reminds me of some sort of Japanese box or miniature temple.  I do like the overall concept.  I would tweek the design by installing black acrylic (or the like) walls between the upper and middle shelves (morticed into the pillars) and have the switches installed in the walls and certainly do something to hide the tube sleeves; a cage or another smaller box on top.

I also have heard elsewhere that many cartridges benefit from above-47K loading.  Is it possible to do easy-access front or rear panel loading changes via a pot or DIP switches?  Various gain settings via easy access pot would be a plus too.  What comes to mind here is the versatility and ease of use of the Ray Samuels Nighthawk phono stage.

http://www.raysamuelsaudio.com/products/f-117

I'm building a more delluxe model with 4 tubes, front panel loading (12 positions) including 1 meg ohm (no load at all). Voting indicates the RM-4 metal case to be most popular. The wood costs more to do and I might offer it on a custom basis.

I am reviving a system of loading I did in the later RM-4s  called "Dynamic Loading" it loads the cartridge without reducing the S/N ratio as much as passive loading. Loading is important to tame the high end of most cartridges MC or MM

I wouldn't want a pot for loading, wiper rectification is horrible. Ill look at Ray's stuff.  I'm  also giving 6 gain positions on the front. Dual mono and dual power supplies.

[Clio09]

I can do all that. But just why do you need that? There is no advantage in balancing a battery powered preamp or buffering 3K ohms unless you are running many many meters of cable to your neighbors house.

With a volume control as part of the design I'd be running direct to amp which requires 25' - 30' of interconnect cable.

[Roger A. Modjeski]

With a volume control as part of the design I'd be running direct to amp which requires 25' - 30' of interconnect cable.

I'd have a passive volume pot on mine but the majority of people don't want one and it actually degrades the product in their mind. There is always pot in a box, or in your case, active pot in a box that will run your cables.

I will likely make a physically matching, low gain, very very quiet line stage with transformer output and most likely transformer volume control. I'm getting less fond of resistive pots for really good sound over the long term.

[Clio09]

A passive volume control in the phono stage wouldn't bother me. I have used passive volume controls pretty exclusively for about 5 years now. Both resistive and TVC. I'd be interested in why you are growing less fond of the resistive passive. Have you ever done anything with light dependent resistors (LDR's)?

The best passive preamp I have heard is the Lightspeed attenuator which uses LDR technology. Works great with the EM-7 and RM-10. There is another preamp called The Truth that is an active buffer (video opamps) that uses this technology as well. Since you are considering a low gain active preamp with a TVC as the attenuator perhaps LDRs could be an option for that, or the phono stage as well. Overall I'd prefer the phono stage and volume control in one box to eliminate the need for an extra set of cables.

[Roger A. Modjeski]

A passive volume control in the phono stage wouldn't bother me. I have used passive volume controls pretty exclusively for about 5 years now. Both resistive and TVC. I'd be interested in why you are growing less fond of the resistive passive. Have you ever done anything with light dependent resistors (LDR's)?

The best passive preamp I have heard is the Lightspeed attenuator which uses LDR technology. Works great with the EM-7 and RM-10. There is another preamp called The Truth that is an active buffer (video opamps) that uses this technology as well. Since you are considering a low gain active preamp with a TVC as the attenuator perhaps LDRs could be an option for that, or the phono stage as well. Overall I'd prefer the phono stage and volume control in one box to eliminate the need for an extra set of cables.

I put a volume control in for myself but I find that I am in the minority. Of course was in the minority about banana jacks 20 years ago and now people want them.

I have a lot of experience with LDR's I dont see any sonic advantage and I wonder how well the two channels stay in balance... how the heck do they do that?