I just made an amp upgrade and need some assistance with connecting it to my system.
I've been running a mid-1980's vintage Yamaha Integrated Amp, model A-700. My sources are a Meridian 508.20 CDP and a Music Hall MMF.7 Turntable (with Eroica Cartridge). Speakers are LSi9s.
After a long upgrade waiting period, I just purchased a McCormack DNA-125 Amp and I am going to integrate it into the system. Until I can afford a preamp upgrade (I've had my eye on an Audible Illusions M3A) I intend to use the preamp and phono-pre section of the Yamaha Integrated amp. That is to say I want to BYPASS the amplifier section of the A-700 and just use the Preamp and Phono Pre sections of the Yamaha.
Question: To effect this, how do I connect the Yamaha Integrated to the McCormack Amp? Do I plug ICs from the McCormack to the A-700's TAPE OUT jacks [the Yamaha has 2 tape loops: TAPE IN/OUT A, TAPE IN/OUT B].
You must have pre amp outputs to take a signal from the Yamaha. The tape outs are not controlled by the volume control of the Yahama and you would therefore be running a full voltage signal into the power amp, think running the system with the volume control wide open. If the power amp has gain controls accessible for easy operation, you could get by with the tape outs though tape outputs are not at the correct impedance for driving a power amp and would therefore limit your cable length and ultimately affect the sound quality to some degree.
You have one other single but poor option which would be to run a passive pre amp configuration from the tape outs to the power amp. This would place a volume control in line between the Yamaha and the McCormack. Thing is a good passive pre amp isn't cheap and, given the limitations of a passive system control running from the not-correct tape output impedance, you might as well wait until you can afford an active pre amp such as the AI.
Thanks for the answer. I'm pleased with the price I got on the McCormack, it fits in with your idea of 'free' audio Jan.
So there's three options now: 1)buy a preamp. (Unfortunately, I do not have the funds, unless I buy something REALLY inexpensive as a stop gap solution - and with a MC phono stage as I have a TT here - that I can resell for what I paid down the road).
2) Hold onto the McCormack, unused, until I can afford a preamp.
3)Hack the Yamaha? Is this doable and worth the effort? Just how involved would it be to modify the Yamaha to include an output jack? I had asked a member of this forum 3 years back for a schematic of the Yamaha, but he never forwarded it, I'm sure I could locate one if I searched harder. I have some basic electronics skills. What would an alteration like this involve?
"Could we not run the rec out from the Yammy and use the rec level as a vc?'
I don't see a tape deck in this system. The Yamaha itself doesn't have any record level controls. Where do you set rec level? If there is such a thing as a tape deck in this system, yes, the record level set would lower the volume. However, this would be about as jerry-rigged a system as I have ever seen. Passing the signal through a tape deck just to get a volume control out of the level set would not be good for the signal. But it would work. So would soldering in a $5 potentiometer from Radio Shack. So would running out from the headphone output through adapters. So would hooking the speaker outs to the amp with a big load resistor in the middle. If we get down to the point of just hooking sh!t up to make a signal flow from point A to point B, we might as well give up on this "hifi" thing.
"Is this doable and worth the effort?"
Sorry, I do not condone "poking" around inside amplifiers. If you don't know whether this can be done, you're not the person to do the job. If you can find someone to work on this amplifier, ask them how much they would charge to do the job. Then consider whether that money would be better off put in savings for a real pre amp.
If you can spend about $250, you can buy a Bellari phono pre amp. This has a volume control for the output. You could use the vc for the phono section but you'd still be swapping cables all the time.
I would suggest you just wait until you can afford to buy something that really works for this system. Look at the Audible Illusions 2C or 2D, they very close to the quality of the 3 and cost quite a bit less.
"If you can spend about $250, you can buy a Bellari phono pre amp. This has a volume control for the output. You could use the vc for the phono section but you'd still be swapping cables all the time. "
Jan, isn't that essentially just a phono pre? They go for about $160 used so the price is doable. I'd need to listen to CDs, LPS, and my digital music server...are you saying cables would need to be swapped each time I switched sources? If so, it would be WAY too much trouble.
I will likely have to buy a used preamp w/MM phono stage for under $300 that I can resell and get my money back down the road [the other option is to sell the McCormack and re-buy it later, which seems foolish without even listening to it in my system].
The issue is that I have other system upgrade priorities to make. In a month or two I will have two additional rooms to supply music to, so I will need a couple more pairs of speakers. I need to upgrade my bare bones Apple music server (now, just a cheap mini>RCA cable from computer to A-700) perhaps resulting in selling my CDP and using the funds to purchase a better DAC. I also will need buy the server/router/wireless(?) hardware to stream music to these other two rooms (which may mean using the Yamaha A-700 with its two pairs of speaker outputs to drive the two new secondary speakers pairs and install the McCormack in my main listening room). It's also time for an audio rack. Big changes and system expansion: bad timing financially for a serious preamp upgrade.
Carver at one time made an accessory to take speaker level outputs and allow you to run an amp from them.....It was small and not expensive which means simple. Was it an impedence matching transformer? Just a resistor net? Who knows?
The other, VERY MUCH more desperate way would be the poke around method. If you can identify the preamp board and the amp board in the yamaha, it is possible to do a snip/solder and make your own jumper out. DO NOT try this if you aren't willing to take a chance. I did one by this method a long time ago. I just cracked the case and it was obvious where the pre/main interface was. I used this for a couple years until I could afford the pre I wanted. I used 24" pigtails with male RCA on the other end.
I'm not trying to argue with Leo but, for 300 bucks, why risk electrocution? "Poking around" is dangerous. Like I said most of what I listed is better than what you own. Start cutting circuit boards on the A700 and what you own will be worth even less.
Yeah, what was I thinking? In the case of my OLD Kenwood, it was obvious where the jumpers were, I was probably 22 and the risk of saving a few bucks too enticing. That it worked, in looking back, was kind of neat, but NOT to be recommended. Would I do so again......Probably NOT with modern stuff that comes all on 1 board. Couldn't figure it out, probably. I got away with it once and count myself lucky...but it was fun.
Based on the good advice offered (as well as the lack of a schematic, the effort needed, and my inexperience...although that hasn't stopped me in the past ; ) I bought a separate pre-amp.