Psilonaught

DHT preamp with balanced inputs/ outputs and remote?

Recommended Posts

10 minutes ago, Non-Smoking Man said:

I know that you are thrilled with your speakers having gone active and I know from that thread that you are currently using an analogue active external crossover (hence your interest in my Marchand DX9 active xo).

My question, James,is, given the crossover has balanced connections, which is the higher priority for you: that the pre amp be balanced or that it be a DHT?

Jack

Good question- I could live with RCA if I had to but would prefer not to. It sounds like David can build me what I want, as a two box solution, so going to pursue that option seriously.

Share this post


Link to post
Share on other sites
Super Dealer
10 minutes ago, Non-Smoking Man said:

I know that you are thrilled with your speakers having gone active and I know from that thread that you are currently using an analogue active external crossover (hence your interest in my Marchand DX9 active xo).

My question, James,is, given the crossover has balanced connections, which is the higher priority for you: that the pre amp be balanced or that it be a DHT?

Jack

Jack,

I'm not sure why you imply it's one or the other........The decision process is:

1. Find a good well-tested circuit (which will be single ended)

2. Implement in balanced mode with the best input /output txs within budget

Ergo job done.

This link here https://adaudio.wordpress.com/2020/11/07/satchmo-preamp-balanced-version/.    shows the results of exactly that process done with my Satchmo 3 pre, and using relatively budget transformers etc

David

Share this post


Link to post
Share on other sites

I've been reading that a Nelson First Watt is a killer combination with a DHT preamp.

Apparently they are exceptional together.

Anyone care to comment? 

The F6 is 50w which might just be enough to drive my tweeter/ midrange section.

Share this post


Link to post
Share on other sites
1 hour ago, Psilonaught said:

I've been reading that a Nelson First Watt is a killer combination with a DHT preamp.

Apparently they are exceptional together.

Anyone care to comment? 

The F6 is 50w which might just be enough to drive my tweeter/ midrange section.

Nelson Pass likes Class A amps, which is closer to SE tube amps. I've heard a SIT amp - not Pass but one based on Sony devices - and it is wonderful, very close to the best tubes. Clean and transparent. I was very impressed. Now, there are Pass SIT amps though they are rare and expensive. They will be more subtle than the usual First Watt devices. I can't comment on "killer combination" - it's more likely that they're both very good sounds and fairly similar. 

If you're talking about a "combination" of tube preamp and solid state amp, then you'll need a step down transformer on the output to achieve a low impedance. I generally use a Lundahl LL1660 but there are various options. This then means you have to decide how much amplification you actually need from your preamp, and in the light of that whether it will be one or two stages. If the amplification is very small, you're basically using the preamp as a buffer. 

Share this post


Link to post
Share on other sites
1 hour ago, pmcuk said:

Nelson Pass likes Class A amps, which is closer to SE tube amps. I've heard a SIT amp - not Pass but one based on Sony devices - and it is wonderful, very close to the best tubes. Clean and transparent. I was very impressed. Now, there are Pass SIT amps though they are rare and expensive. They will be more subtle than the usual First Watt devices. I can't comment on "killer combination" - it's more likely that they're both very good sounds and fairly similar. 

If you're talking about a "combination" of tube preamp and solid state amp, then you'll need a step down transformer on the output to achieve a low impedance. I generally use a Lundahl LL1660 but there are various options. This then means you have to decide how much amplification you actually need from your preamp, and in the light of that whether it will be one or two stages. If the amplification is very small, you're basically using the preamp as a buffer. 

I'll be initially using it with a very beefy 150w class A power amp

Share this post


Link to post
Share on other sites

Juancho - basically I hadnt taken in the post referring to your balanced option Sancho, which does provide what James is looking for. My question just reflected the lack of known options. In fact its got ME thinking..(as I have a balanced system)

pmck - (On the need for a step down transformer for impedance matching). Would the fact that in my horn system I use an active analogue crossover (Ashly) with gain alter your point about one and two stage pre amps. Put another way, could the balanced Satchmo be used as the pre amp in a multiway horn system where the pre is 'driving' the Ashly (in my case) or whatever brand James is using currently?

Jack

Share this post


Link to post
Share on other sites
13 minutes ago, Non-Smoking Man said:

Juancho - basically I hadnt taken in the post referring to your balanced option Sancho, which does provide what James is looking for. My question just reflected the lack of known options. In fact its got ME thinking..(as I have a balanced system)

pmck - (On the need for a step down transformer for impedance matching). Would the fact that in my horn system I use an active analogue crossover (Ashly) with gain alter your point about one and two stage pre amps. Put another way, could the balanced Satchmo be used as the pre amp in a multiway horn system where the pre is 'driving' the Ashly (in my case) or whatever brand James is using currently?

Jack

yeah that's a good point- I use an active crossover as well as a preamp too

Share this post


Link to post
Share on other sites
Moderator
1 hour ago, pmcuk said:

I've heard a SIT amp - not Pass but one based on Sony devices - and it is wonderful. 

Pete's one?

If so, I agree. Mind you, also one of the best convection heaters I've come across as well :cool:

Share this post


Link to post
Share on other sites
Super Dealer
18 minutes ago, Non-Smoking Man said:

J

pmck - (On the need for a step down transformer for impedance matching). Would the fact that in my horn system I use an active analogue crossover (Ashly) with gain alter your point about one and two stage pre amps. Put another way, could the balanced Satchmo be used as the pre amp in a multiway horn system where the pre is 'driving' the Ashly (in my case) or whatever brand James is using currently?

Jack

Both level and output impedance are simply design criteria. If no gain ie a buffer is all that's needed that's what can be built. Similarly, I would always design output impedance to be as low as practical in case equipment is changed or long leads used.

David

Share this post


Link to post
Share on other sites
1 hour ago, rabski said:

Pete's one?

If so, I agree. Mind you, also one of the best convection heaters I've come across as well :cool:

Yes, indeed, Pete's one. Lovely guy. Used to post here but haven't heard from him recently. He had the most amazing collection of arcane horn units I've ever seen - Japanese and who knows what else....

Share this post


Link to post
Share on other sites

Pete was part of the cohort that left here over 3 years ago during a period of unpleasantness and dissatisfaction with the direction the site was being taken, that thankfully hasn’t returned since

Share this post


Link to post
Share on other sites

Looks like the Pass SIT isn't powerful enough for my application unfortunately. Does anyone have link to the bespoke Sony SIT unit being discussed for curiousity?

Share this post


Link to post
Share on other sites
Moderator
1 hour ago, pmcuk said:

Yes, indeed, Pete's one. Lovely guy. Used to post here but haven't heard from him recently. He had the most amazing collection of arcane horn units I've ever seen - Japanese and who knows what else....

I'm in touch, though not frequently enough. Have no idea what he has done with the WE horns though. My still unfinished 300B PPs are his design.

Share this post


Link to post
Share on other sites
24 minutes ago, Psilonaught said:

Looks like the Pass SIT isn't powerful enough for my application unfortunately. Does anyone have link to the bespoke Sony SIT unit being discussed for curiousity?

Share this post


Link to post
Share on other sites
16 minutes ago, Psilonaught said:

Looks like the Pass SIT isn't powerful enough for my application unfortunately. Does anyone have link to the bespoke Sony SIT unit being discussed for curiousity?

You've fallen upon yet another design which isn't commercially available. The Sony SIT devices are long gone. Nelson Pass had to commission some new devices, which was quite a brave move. The amps run very hot - huge heatsinks. That's probably one reason that the amps weren't very commercial and the devices went obsolete. Big shame - SIT devices are special. One or two still exist on eBay. Pete might build one if he has the time, but that's a very big if. 

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • Recently Browsing   0 members

    No registered users viewing this page.